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  Subjects -> ENGINEERING (Total: 2449 journals)
    - CHEMICAL ENGINEERING (208 journals)
    - CIVIL ENGINEERING (208 journals)
    - ELECTRICAL ENGINEERING (116 journals)
    - ENGINEERING (1288 journals)
    - ENGINEERING MECHANICS AND MATERIALS (394 journals)
    - HYDRAULIC ENGINEERING (56 journals)
    - INDUSTRIAL ENGINEERING (81 journals)
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CIVIL ENGINEERING (208 journals)                  1 2 | Last

Showing 1 - 200 of 208 Journals sorted alphabetically
ACI Structural Journal     Full-text available via subscription   (Followers: 20)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
Acta Structilia : Journal for the Physical and Development Sciences     Open Access   (Followers: 3)
Advances in Civil Engineering     Open Access   (Followers: 41)
Advances in Structural Engineering     Full-text available via subscription   (Followers: 33)
Agregat     Open Access   (Followers: 1)
Ambiente Construído     Open Access   (Followers: 1)
American Journal of Civil Engineering and Architecture     Open Access   (Followers: 35)
Architectural Engineering     Open Access   (Followers: 5)
Architecture and Engineering     Open Access  
Architecture, Civil Engineering, Environment     Open Access  
Archives of Civil and Mechanical Engineering     Full-text available via subscription   (Followers: 3)
Archives of Civil Engineering     Open Access   (Followers: 12)
Archives of Hydro-Engineering and Environmental Mechanics     Open Access   (Followers: 2)
ATBU Journal of Environmental Technology     Open Access   (Followers: 4)
Australian Journal of Structural Engineering     Full-text available via subscription   (Followers: 7)
Baltic Journal of Road and Bridge Engineering     Open Access   (Followers: 1)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 10)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 3)
Berkeley Planning Journal     Open Access   (Followers: 5)
Bioinspired Materials     Open Access   (Followers: 5)
Bridge Structures : Assessment, Design and Construction     Hybrid Journal   (Followers: 14)
Building & Management     Open Access   (Followers: 2)
Building and Environment     Hybrid Journal   (Followers: 15)
Building Women     Full-text available via subscription  
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 15)
Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture     Open Access   (Followers: 6)
Canadian Journal of Civil Engineering     Hybrid Journal   (Followers: 13)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 11)
Case Studies in Structural Engineering     Open Access   (Followers: 9)
Cement and Concrete Composites     Hybrid Journal   (Followers: 20)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 3)
Challenge Journal of Structural Mechanics     Open Access   (Followers: 5)
Change Over Time     Full-text available via subscription   (Followers: 2)
Civil and Environmental Engineering     Open Access   (Followers: 8)
Civil and Environmental Engineering Reports     Open Access   (Followers: 8)
Civil and Environmental Research     Open Access   (Followers: 17)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Civil Engineering and Architecture     Open Access   (Followers: 23)
Civil Engineering and Environmental Systems     Hybrid Journal   (Followers: 3)
Civil Engineering and Technology     Open Access   (Followers: 12)
Civil Engineering Dimension     Open Access   (Followers: 11)
Civil Engineering Infrastructures Journal     Open Access   (Followers: 1)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Composite Structures     Hybrid Journal   (Followers: 290)
Computer-aided Civil and Infrastructure Engineering     Hybrid Journal   (Followers: 11)
Computers & Structures     Hybrid Journal   (Followers: 37)
Concrete Research Letters     Open Access   (Followers: 7)
Construction Economics and Building     Open Access   (Followers: 4)
Construction Engineering     Open Access   (Followers: 11)
Construction Management and Economics     Hybrid Journal   (Followers: 21)
Constructive Approximation     Hybrid Journal  
Curved and Layered Structures     Open Access   (Followers: 3)
DFI Journal : The Journal of the Deep Foundations Institute     Hybrid Journal   (Followers: 1)
Earthquake Engineering and Structural Dynamics     Hybrid Journal   (Followers: 17)
Enfoque UTE     Open Access   (Followers: 4)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 7)
Engineering Structures     Hybrid Journal   (Followers: 13)
Engineering Structures and Technologies     Open Access   (Followers: 2)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 10)
Environmental Geotechnics     Hybrid Journal   (Followers: 5)
European Journal of Environmental and Civil Engineering     Hybrid Journal   (Followers: 10)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 19)
Frontiers in Built Environment     Open Access   (Followers: 1)
Frontiers of Structural and Civil Engineering     Hybrid Journal   (Followers: 6)
Geomaterials     Open Access   (Followers: 3)
Geosystem Engineering     Hybrid Journal   (Followers: 2)
Geotechnik     Hybrid Journal   (Followers: 4)
Géotechnique Letters     Hybrid Journal   (Followers: 8)
GISAP : Technical Sciences, Construction and Architecture     Open Access  
HBRC Journal     Open Access   (Followers: 2)
Hormigón y Acero     Full-text available via subscription  
HVAC&R Research     Hybrid Journal  
Indonesian Journal of Urban and Environmental Technology     Open Access  
Indoor and Built Environment     Hybrid Journal   (Followers: 3)
Infrastructure Asset Management     Hybrid Journal   (Followers: 3)
Infrastructures     Open Access  
Ingenio Magno     Open Access   (Followers: 1)
Insight - Non-Destructive Testing and Condition Monitoring     Full-text available via subscription   (Followers: 30)
International Journal for Service Learning in Engineering     Open Access  
International Journal of 3-D Information Modeling     Full-text available via subscription   (Followers: 3)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 17)
International Journal of Civil, Mechanical and Energy Science     Open Access   (Followers: 2)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 15)
International Journal of Condition Monitoring     Full-text available via subscription   (Followers: 2)
International Journal of Construction Engineering and Management     Open Access   (Followers: 10)
International Journal of Engineering and Geosciences     Open Access  
International Journal of Geo-Engineering     Open Access   (Followers: 3)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Pavement Research and Technology     Open Access   (Followers: 6)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of Steel Structures     Hybrid Journal   (Followers: 2)
International Journal of Structural Engineering     Hybrid Journal   (Followers: 9)
International Journal of Structural Integrity     Hybrid Journal   (Followers: 2)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Built Environment     Open Access   (Followers: 5)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 8)
International Journal on Pavement Engineering & Asphalt Technology     Open Access   (Followers: 7)
International Journal Sustainable Construction & Design     Open Access   (Followers: 2)
Journal of Applied Research in Water and Wastewater     Open Access   (Followers: 1)
Journal of Bridge Engineering     Full-text available via subscription   (Followers: 13)
Journal of Building Engineering     Hybrid Journal   (Followers: 2)
Journal of Building Materials and Structures     Open Access   (Followers: 2)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Journal of Civil Engineering     Open Access  
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 15)
Journal of Civil Engineering and Management     Open Access   (Followers: 7)
Journal of Civil Engineering and Science     Open Access   (Followers: 9)
Journal of Civil Engineering Research     Open Access   (Followers: 7)
Journal of Civil Engineering, Science and Technology     Open Access   (Followers: 1)
Journal of Civil Society     Hybrid Journal   (Followers: 5)
Journal of Civil Structural Health Monitoring     Hybrid Journal   (Followers: 4)
Journal of Composites     Open Access   (Followers: 78)
Journal of Composites for Construction     Full-text available via subscription   (Followers: 13)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 23)
Journal of Construction Engineering     Open Access   (Followers: 9)
Journal of Construction Engineering and Management     Full-text available via subscription   (Followers: 17)
Journal of Constructional Steel Research     Hybrid Journal   (Followers: 6)
Journal of Earth Sciences and Geotechnical Engineering     Open Access   (Followers: 4)
Journal of Fluids and Structures     Hybrid Journal   (Followers: 6)
Journal of Frontiers in Construction Engineering     Open Access   (Followers: 2)
Journal of Green Building     Full-text available via subscription   (Followers: 10)
Journal of Highway and Transportation Research and Development (English Edition)     Full-text available via subscription   (Followers: 14)
Journal of Infrastructure Systems     Full-text available via subscription   (Followers: 19)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Marine Science and Engineering     Open Access   (Followers: 1)
Journal of Materials and Engineering Structures     Open Access   (Followers: 5)
Journal of Materials in Civil Engineering     Full-text available via subscription   (Followers: 8)
Journal of Nondestructive Evaluation     Hybrid Journal   (Followers: 9)
Journal of Performance of Constructed Facilities     Full-text available via subscription   (Followers: 3)
Journal of Pipeline Systems Engineering and Practice     Full-text available via subscription   (Followers: 6)
Journal of Rehabilitation in Civil Engineering     Open Access   (Followers: 3)
Journal of Solid Waste Technology and Management     Full-text available via subscription   (Followers: 1)
Journal of Structural Engineering     Full-text available via subscription   (Followers: 35)
Journal of Structural Fire Engineering     Full-text available via subscription   (Followers: 6)
Journal of Structural Mechanics     Open Access   (Followers: 1)
Journal of Structures     Open Access   (Followers: 4)
Journal of Sustainable Architecture and Civil Engineering     Open Access   (Followers: 3)
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 1)
Journal of the Civil Engineering Forum     Open Access  
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 2)
Journal of Water and Environmental Nanotechnology     Open Access  
Journal of Water and Wastewater / Ab va Fazilab     Open Access  
Jurnal Spektran     Open Access   (Followers: 1)
Jurnal Teknik Sipil     Open Access  
Jurnal Teknik Sipil dan Perencanaan     Open Access   (Followers: 1)
Konstruksia     Open Access  
KSCE Journal of Civil Engineering     Hybrid Journal   (Followers: 2)
Latin American Journal of Solids and Structures     Open Access   (Followers: 4)
Materiales de Construcción     Open Access   (Followers: 1)
Mathematical Modelling in Civil Engineering     Open Access   (Followers: 4)
Media Komunikasi Teknik Sipil     Open Access  
Mokslas – Lietuvos ateitis / Science – Future of Lithuania     Open Access  
Nondestructive Testing And Evaluation     Hybrid Journal   (Followers: 15)
npj Materials Degradation     Open Access  
Obras y Proyectos     Open Access   (Followers: 1)
Open Journal of Civil Engineering     Open Access   (Followers: 9)
Periodica Polytechnica Civil Engineering     Open Access  
Photonics and Nanostructures - Fundamentals and Applications     Hybrid Journal   (Followers: 4)
Practice Periodical on Structural Design and Construction     Full-text available via subscription   (Followers: 3)
Proceedings of the Institution of Civil Engineers - Bridge Engineering     Hybrid Journal   (Followers: 8)
Proceedings of the Institution of Civil Engineers - Civil Engineering     Hybrid Journal   (Followers: 14)
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law     Hybrid Journal   (Followers: 10)
Proceedings of the Institution of Civil Engineers - Municipal Engineer     Hybrid Journal   (Followers: 2)
Proceedings of the Institution of Civil Engineers - Structures and Buildings     Hybrid Journal   (Followers: 3)
Promet : Traffic &Transportation     Open Access  
Random Structures and Algorithms     Hybrid Journal   (Followers: 5)
Recent Trends In Civil Engineering & Technology     Full-text available via subscription   (Followers: 5)
Research in Nondestructive Evaluation     Hybrid Journal   (Followers: 6)
Resilience     Open Access   (Followers: 1)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Revista Sul-Americana de Engenharia Estrutural     Open Access  
Road Materials and Pavement Design     Hybrid Journal   (Followers: 11)
Russian Journal of Nondestructive Testing     Hybrid Journal   (Followers: 5)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 61)
Selected Scientific Papers - Journal of Civil Engineering     Open Access   (Followers: 3)
Slovak Journal of Civil Engineering     Open Access   (Followers: 2)
Soils and foundations     Full-text available via subscription   (Followers: 5)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 3)
Structural and Multidisciplinary Optimization     Hybrid Journal   (Followers: 11)
Structural Concrete     Hybrid Journal   (Followers: 11)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 8)
Structural Engineering International     Full-text available via subscription   (Followers: 11)
Structural Mechanics of Engineering Constructions and Buildings     Open Access   (Followers: 1)
Structural Safety     Hybrid Journal   (Followers: 6)
Structural Survey     Hybrid Journal  
Structure     Full-text available via subscription   (Followers: 24)
Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance     Hybrid Journal   (Followers: 12)
Structures     Hybrid Journal   (Followers: 1)
Study of Civil Engineering and Architecture     Open Access   (Followers: 10)
Superlattices and Microstructures     Hybrid Journal   (Followers: 2)
Surface Innovations     Hybrid Journal  
Technical Report Civil and Architectural Engineering     Open Access   (Followers: 1)
Teknik     Open Access  
Territorium : Revista Portuguesa de riscos, prevenção e segurança     Open Access  
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)

        1 2 | Last

Journal Cover
Journal of Marine Science and Engineering
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2077-1312
Published by MDPI Homepage  [205 journals]
  • JMSE, Vol. 6, Pages 74: Failure of Grass Covered Flood Defences with Roads
           on Top Due to Wave Overtopping: A Probabilistic Assessment Method

    • Authors: Juan P. Aguilar-López, Jord J. Warmink, Anouk Bomers, Ralph M. J. Schielen, Suzanne J. M. H. Hulscher
      First page: 74
      Abstract: Hard structures, i.e., roads, are commonly found over flood defences, such as dikes, in order to ensure access and connectivity between flood protected areas. Several climate change future scenario studies have concluded that flood defences will be required to withstand more severe storms than the ones used for their original design. Therefore, this paper presents a probabilistic methodology to assess the effect of a road on top of a dike: it gives the failure probability of the grass cover due to wave overtopping over a wide range of design storms. The methodology was developed by building two different dike configurations in computational fluid dynamics Navier–Stokes solution software; one with a road on top and one without a road. Both models were validated with experimental data collected from field-scale experiments. Later, both models were used to produce data sets for training simpler and faster emulators. These emulators were coupled to a simplified erosion model which allowed testing storm scenarios which resulted in local scouring conditioned statistical failure probabilities. From these results it was estimated that the dike with a road has higher probabilities (5 × 10−5 > Pf >1 × 10−4) of failure than a dike without a road (Pf < 1 × 10−6) if realistic grass quality spatial distributions were assumed. The coupled emulator-erosion model was able to yield realistic probabilities, given all the uncertainties in the modelling process and it seems to be a promising tool for quantifying grass cover erosion failure.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-22
      DOI: 10.3390/jmse6030074
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 75: Free Surface Characteristics of Flow around Two
           Side-by-Side Circular Cylinders

    • Authors: Dengsong Li, Qing Yang, Xudong Ma, Guangqing Dai
      First page: 75
      Abstract: The three-dimensional free surface characteristics of flow around two equal diameter cylinders in a side-by-side arrangement were studied numerically. The flow fields were simulated with a three-dimensional finite volume method based on the RNG k-ɛ model for Reynolds number Re = 1.0 × 104. The volume-of-fluid method was applied to track air–water interfaces. Computations were performed for gap ratios of 1.25, 1.5, and 1.75 to examine the influence of the gap between two cylinders, and for distance to diameter ratios of 8.0 and 1.0 to study the wall proximity effects. The model was verified by comparing it with the other numerical and experimental results. The results indicated that the evolution of the free surface was periodic in time scale. A weak hydraulic jump occurs in the wake flow. Moreover, a significant difference between upstream and downstream free surface elevations exists in the vicinity of the cylinder. A runup in front of the cylinder and a ‘depression’ around the side edge were also observed. Computational results showed that the flow near the two cylinders was pushed outwards, and the flow between the cylinder and the wall was deflected inwards by the wall. The vortex structures on and near the free surface were closely correlated with the free surface. The shedding vortex far from the free surface was not affected.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-25
      DOI: 10.3390/jmse6030075
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 76: Projected 21st Century Coastal Flooding in the
           Southern California Bight. Part 2: Tools for Assessing Climate
           Change-Driven Coastal Hazards and Socio-Economic Impacts

    • Authors: Li Erikson, Patrick Barnard, Andrea O’Neill, Nathan Wood, Jeanne Jones, Juliette Finzi Hart, Sean Vitousek, Patrick Limber, Maya Hayden, Michael Fitzgibbon, Jessica Lovering, Amy Foxgrover
      First page: 76
      Abstract: This paper is the second of two that describes the Coastal Storm Modeling System (CoSMoS) approach for quantifying physical hazards and socio-economic hazard exposure in coastal zones affected by sea-level rise and changing coastal storms. The modelling approach, presented in Part 1, downscales atmospheric global-scale projections to local scale coastal flood impacts by deterministically computing the combined hazards of sea-level rise, waves, storm surges, astronomic tides, fluvial discharges, and changes in shoreline positions. The method is demonstrated through an application to Southern California, United States, where the shoreline is a mix of bluffs, beaches, highly managed coastal communities, and infrastructure of high economic value. Results show that inclusion of 100-year projected coastal storms will increase flooding by 9–350% (an additional average 53.0 ± 16.0 km2) in addition to a 25–500 cm sea-level rise. The greater flooding extents translate to a 55–110% increase in residential impact and a 40–90% increase in building replacement costs. To communicate hazards and ranges in socio-economic exposures to these hazards, a set of tools were collaboratively designed and tested with stakeholders and policy makers; these tools consist of two web-based mapping and analytic applications as well as virtual reality visualizations. To reach a larger audience and enhance usability of the data, outreach and engagement included workshop-style trainings for targeted end-users and innovative applications of the virtual reality visualizations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-02
      DOI: 10.3390/jmse6030076
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 77: A Novel Iterative Water Refraction Correction
           Algorithm for Use in Structure from Motion Photogrammetric Pipeline

    • Authors: Dimitrios Skarlatos, Panagiotis Agrafiotis
      First page: 77
      Abstract: Photogrammetry using structure from motion (SfM) techniques has evolved into a powerful tool for a variety of applications. Nevertheless, limits are imposed when two-media photogrammetry is needed, in cases such as submerged archaeological site documentation. Water refraction poses a clear limit on photogrammetric applications, especially when traditional methods and standardized pipelines are followed. This work tries to estimate the error introduced to depth measurements when no refraction correction model is used and proposes an easy to implement methodology in a modern photogrammetric workflow dominated by SfM and multi-view stereo (MVS) techniques. To be easily implemented within current software and workflow, this refraction correction approach is applied at the photo level. Results over two test sites in Cyprus against reference data suggest that despite the assumptions and approximations made the proposed algorithm can reduce the effect of refraction to two times the ground pixel size, regardless of the depth.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-02
      DOI: 10.3390/jmse6030077
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 78: Resonantly Forced Baroclinic Waves in the Oceans:
           Subharmonic Modes

    • Authors: Jean-Louis Pinault
      First page: 78
      Abstract: The study of resonantly forced baroclinic waves in the tropical oceans at mid-latitudes is of paramount importance to advancing our knowledge in fields that investigate the El Niño–Southern Oscillation (ENSO), the decadal climate variability, or the resonant feature of glacial-interglacial cycles that are a result of orbital forcing. Indeed, these baroclinic waves, the natural period of which coincides with the forcing period, have a considerable impact on ocean circulation and in climate variability. Resonantly Forced Waves (RFWs) are characterized by antinodes at sea surface height anomalies and nodes where modulated geostrophic currents ensure the transfer of warm water from an antinode to another, reflecting a quasi-geostrophic motion. Several RFWs of different periods are coupled when they share the same node, which involves the geostrophic forces at the basin scale. These RFWs are subject to a subharmonic mode locking, which means that their average periods are a multiple of the natural period of the fundamental wave, that is, one year. This property of coupled oscillator systems is deduced from the Hamiltonian (the energy) of the Caldirola–Kanai (CK) oscillator. In this article, it is shown how the CK oscillator, which is usually used to develop a phenomenological single-particle approach, is transposable to RFWs. Subharmonic modes ensure the durability of the resonant dissipative system, with each oscillator transferring as much interaction energy to all the others that it receives periodically.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-02
      DOI: 10.3390/jmse6030078
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 79: Significance of Fluvial Sediment Supply in
           Coastline Modelling at Tidal Inlets

    • Authors: Janaka Bamunawala, Shreedhar Maskey, Trang Minh Duong, Ad van der Spek
      First page: 79
      Abstract: The sediment budget associated with future coastline change in the vicinity of tidal inlets consists of four components; sea level rise-driven landward movement of the coastline (i.e., the Bruun effect), basin infilling effect due to sea level rise-induced increase in accommodation space, basin volume change due to variation in river discharge, and coastline change caused by change in fluvial sediment supply. These four components are affected by climate change and/or anthropogenic impacts. Despite this understanding, holistic modelling techniques that account for all the aforementioned processes under both climate change and anthropogenic influences are lacking. This manuscript presents the applications of a newly-developed reduced complexity modelling approach that accounts for both climate change and anthropogenically-driven impacts on future coastline changes. Modelled results corresponding to the year 2100 indicate considerable coastline recessions at Wilson Inlet (152 m) and the Swan River system (168 m) in Australia and Tu Hien Inlet (305 m) and Thuan An Inlet (148 m) in Vietnam. These results demonstrate that coastline models should incorporate both climate change and anthropogenic impacts to quantify future changes in fluvial sediment supply to coasts to achieve better estimates of total coastline changes at tidal inlets. Omission of these impacts is one of the major drawbacks in all the existing coastline models that simulate future coastline changes at tidal inlets. A comparison of these modelled future coastline changes with the predictions made by a relevant existing modelling technique (Scale Aggregated Model for Inlet-interrupted Coasts (SMIC)) indicates that the latter method overestimates total coastline recessions at the Swan River system, and the Tu Hien and Thuan An Inlets by 7%, 10%, and 30%, respectively, underlining the significance of integrating both climate change and anthropogenic impacts to assess future coastline changes at tidal inlets.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-03
      DOI: 10.3390/jmse6030079
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 80: Shoreline Change around a River Delta on the
           Cox’s Bazar Coast of Bangladesh

    • Authors: Upal Mahamud, Satoshi Takewaka
      First page: 80
      Abstract: A recent erosional problem around a river delta on the Cox’s Bazar coast was analyzed in this study. The coastline extends from south to north. Rapid erosion has affected some portions of a 24-km road along the coast, and local authorities have attempted to protect the road via revetment. However, the structure was soon buried with sediment because of a growing sand spit along the river delta, and a new area was eroded. Shoreline positions for a 44-year (1972–2016) period were digitized using Landsat images. From the time stack images, we observed a sand spit growing in a northward direction from 2000 to 2015, and the adjacent erosion area extended in the same direction. We employed a numerical model (MIKE21FM SM) for the computation of wave-driven currents and sediment transport along the coast, and attempted to reproduce recent erosional processes. The numerical result shows that net littoral drift is dominant in the northward direction along the coast, which is the same direction of the spit growth observed in the satellite images. A higher amplitude spit induces higher sediment transport compared to a low amplitude spit because of the difference in local incident wave angles resulting in greater positive gradient of the longshore sediment flux distribution, causing erosion in the downcoast.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-04
      DOI: 10.3390/jmse6030080
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 81: A Collaborative European Approach to Accelerating
           Translational Marine Science

    • Authors: Philip Brennecke, Maria I. Ferrante, Ian A. Johnston, David Smith
      First page: 81
      Abstract: Marine environments account for over 90% of the biosphere and hold tremendous potential for biotechnological applications and drug discovery. To fully exploit this potential and develop interesting discoveries into useful molecular tools and successful products, a multidisciplinary approach is indispensable. Here, we introduce the European Marine Biological Research Infrastructure Cluster (EMBRIC), a novel collaborative initiative that aims to facilitate translational marine science and remove existing bottlenecks that are currently impeding blue innovation. In the context of this initiative, pilot projects have been designed to test the functionality of the cluster focusing on two specific sectors of marine biotechnology: (i) the discovery and exploitation of marine natural products and (ii) the marker-assisted selection of desirable traits in aquaculture. EMBRIC brings together the expertise of six European Research Infrastructures on accessing the potential of marine organisms, specifically on the 99% of bacteria yet to be grown in culture, the microalgae, finfish, and shellfish. It improves the throughput and efficiency of workflows for discovery of novel marine products and facilitates projects that require an interdisciplinary approach. The objective is to develop coherent chains of high quality services for access to biological, analytical, and data resources by deploying common underpinning technologies and practices. The connection of academic science with industry is being strengthened by engaging companies, as well as geographically separated public and private-sector communities in the domain of marine biotechnology, and by federating technology transfer services amongst the players involved.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-05
      DOI: 10.3390/jmse6030081
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 82: Possible Criterion to Estimate the Juvenile
           Reference Length of Common Sardine (Strangomera bentincki) off
           Central-Southern Chile

    • Authors: Karen Walker, Antonio Aranis, Javier Contreras-Reyes
      First page: 82
      Abstract: In the last century, the growing evidence that global fisheries are depleting natural resources much faster than they can recover has led to negative processes, like overfishing, being addressed with increasingly complex models and thus mitigating or regulating actions that aim to protect stocks. Said negative processes contain two components: (i) they can diminish the reproductive potential of fish stocks, called over exploitation by recruitment, and (ii) the effect of early capture prevents the full realization of the growth potential, called overfishing by growth. In this article, the structure of common sardine sizes is analyzed. Due to the precise moment in which pre-recruits are incorporated into the exploited phase of the stock is unknown, the estimation of a recruitment size is a hard problem. This problem is addressed by modeling the mean size via a stochastic process, applying models of structural change. A time series (2001–2015) was analyzed on a weekly time scale based on the size structure of the pelagic fishery landings in the central-southern zone of Chile (32∘10′–40∘14′ LS), from the V. to the XIV. Region. Specifically, the evolution of sizes according to macro-zones was studied for the conglomerates identified in two sub-zones, the V.–VIII. and IX.–XIV. Regions. In this context, the reference size for juveniles to cautiously allow the recruitment process of the common sardine from the central-southern zone of Chile was estimated, and the behavior of these sizes was spatially analyzed. Finally, a statistical inferential criterion was established that confirms the mean size of juveniles with a certain margin of error, which allows nonetheless later on to define a fraction that could be protected to avoid overfishing by growth.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-05
      DOI: 10.3390/jmse6030082
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 83: Wave (Current)-Induced Pore Pressure in Offshore
           Deposits: A Coupled Finite Element Model

    • Authors: Chencong Liao, Dongsheng Jeng, Zaibin Lin, Yakun Guo, Qi Zhang
      First page: 83
      Abstract: The interaction between wave and offshore deposits is of great importance for the foundation design of marine installations. However, most previous investigations have been limited to connecting separated wave and seabed sub-models with an individual interface program that transfers loads from the wave model to the seabed model. This research presents a two-dimensional coupled approach to study both wave and seabed processes simultaneously in the same FEM (finite element method) program (COMSOL Multiphysics). In the present model, the progressive wave is generated using a momentum source maker combined with a steady current, while the seabed response is applied with the poro-elastoplastic theory. The information between the flow domain and soil deposits is strongly shared, leading to a comprehensive investigation of wave-seabed interaction. Several cases have been simulated to test the wave generation capability and to validate the soil model. The numerical results present fairly good predictions of wave generation and pore pressure within the seabed, indicating that the present coupled model is a sufficient numerical tool for estimation of wave-induced pore pressure.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-06
      DOI: 10.3390/jmse6030083
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 84: Capturing Physical Dispersion Using a Nonlinear
           Shallow Water Model

    • Authors: Rozita Kian, Juan Horrillo, Andrey Zaytsev, Ahmet Cevdet Yalciner
      First page: 84
      Abstract: Predicting the arrival time of natural hazards such as tsunamis is of very high importance to the coastal community. One of the most effective techniques to predict tsunami propagation and arrival time is the utilization of numerical solutions. Numerical approaches of Nonlinear Shallow Water Equations (NLSWEs) and nonlinear Boussinesq-Type Equations (BTEs) are two of the most common numerical techniques for tsunami modeling and evaluation. BTEs use implicit schemes to achieve more accurate results compromising computational time, while NLSWEs are sometimes preferred due to their computational efficiency. Nonetheless, the term accounting for physical dispersion is not inherited in NLSWEs, calling for their consideration and evaluation. In the present study, the tsunami numerical model NAMI DANCE, which utilizes NLSWEs, is applied to previously reported problems in the literature using different grid sizes to investigate dispersion effects. Following certain conditions for grid size, time step and water depth, the simulation results show a fairly good agreement with the available models showing the capability of NAMI DANCE to capture small physical dispersion. It is confirmed that the current model is an acceptable alternative for BTEs when small dispersion effects are considered.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-09
      DOI: 10.3390/jmse6030084
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 85: Response-Spectrum Uncoupled Analyses for Seismic
           Assessment of Offshore Wind Turbines

    • Authors: Giuseppe Failla, Fabio Santangelo, Gabriele Foti, Fabio Scali, Felice Arena
      First page: 85
      Abstract: According to International Standards and Guidelines, the seismic assessment of offshore wind turbines in seismically-active areas may be performed by combining two uncoupled analyses under wind-wave and earthquake loads, respectively. Typically, the separate earthquake response is calculated by a response-spectrum approach and, for this purpose, structural models of various degrees of complexity may be used. Although response-spectrum uncoupled analyses are currently allowed as alternative to time-consuming fully-coupled simulations, for which dedicated software packages are required, to date no specific studies have been presented on whether accuracy may vary depending on key factors as structural modelling, criteria to calculate wind-wave and earthquake responses, and other relevant issues as the selected support structure, the considered environmental states and earthquake records. This paper will investigate different potential implementations of response-spectrum uncoupled analyses for offshore wind turbines, using various structural models and criteria to calculate the wind-wave and earthquake responses. The case study is a 5-MW wind turbine on two support structures in intermediate waters, under a variety of wind-wave states and real earthquake records. Numerical results show that response-spectrum uncoupled analyses may provide non-conservative results, for every structural model adopted and criteria to calculate wind-wave and earthquake responses. This is evidence that appropriate safety factors should be assumed when implementing response-spectrum uncoupled analyses allowed by International Standards and Guidelines.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-07-09
      DOI: 10.3390/jmse6030085
      Issue No: Vol. 6, No. 3 (2018)
       
  • JMSE, Vol. 6, Pages 29: Wave-Created Mud Suspensions: A Theoretical Study

    • Authors: Jochen Kämpf, Paul Myrow
      First page: 29
      Abstract: We studied wave-created high-density mud suspensions (fluid mud) using a one-dimensional water column (1DV) model that includes k-ε turbulence closure at a high vertical resolution with a vertical grid spacing of 1 mm. The k-ε turbulence model includes two sediment-related dissipation terms associated with vertical density stratification and viscous drag of flows around sediment particles. To this end, the calibrated model reproduces the key characteristics (maximum concentration and thickness) of fluid mud layers created in laboratory experiments over a large range of wave velocities from 10 to 55 cm/s. The findings demonstrate that the equilibrium near-bed mud concentration, Cb, is solely determined from the balance between erosion and deposition fluxes, whereas the thickness of the fluid mud layer is mainly controlled by sediment-induced density stratification, which dissipates turbulence and hence eliminates turbulent sediment diffusivity at the top of the fluid mud layer, the lutocline. Our model stands in contrast to those that suggest that upward sediment diffusion is close to zero at the interface between the fluid mud layer and the overlying fluid. Instead, our model suggests that the upward diffusive flux of fluid mud flows peak at the lutocline and is compensated for enhanced settling fluxes just above it. Our model findings also support the existence of the gelling-ignition process, which is critical for the development of fluid mud beds in modern sedimentary environments.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-27
      DOI: 10.3390/jmse6020029
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 30: The Implications of Oil Exploration off the Gulf
           Coast of Florida

    • Authors: Jake Nelson, Tony Grubesic
      First page: 30
      Abstract: In the United States (U.S.), oil exploration and production remain critical economic engines for local, state, and federal economies. Recently, the U.S. Department of the Interior expressed interest in expanding offshore oil production by making available lease areas in the U.S. Gulf of Mexico, the U.S. West Coast and East Coast, as well as offshore Alaska. With the promise of aiding in energy independence, these new lease areas could help solidify the U.S. as one of the world’s largest oil-producing countries, while at the same time bolstering the local and regional energy job sectors. Of all the newly proposed lease areas, the Gulf Coast of Florida is particularly contentious. Opponents of drilling in the area cite the sensitive ecosystems and the local and state tourism economy that depends heavily on the numerous beaches lining Florida’s coast. In this analysis, we use a data-driven spatial analytic approach combined with advanced oil spill modeling to determine the potential impact of oil exploration off of Florida’s Gulf Coast given a loss-of-control event. It is determined that plume behavior varies drastically depending on the location of the spill but that overall impacts are comparable across all spill scenario sites, highlighting the necessity of contingency-type analyses. Implications for spill response are also discussed.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-02
      DOI: 10.3390/jmse6020030
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 31: Control of Wave Energy Converters with Discrete
           Displacement Hydraulic Power Take-Off Units

    • Authors: Shangyan Zou, Ossama Abdelkhalik
      First page: 31
      Abstract: The control of ocean Wave Energy Converters (WECs) impacts the harvested energy. Several control methods have been developed over the past few decades to maximize the harvested energy. Many of these methods were developed based on an unconstrained dynamic model assuming an ideal power take-off (PTO) unit. This study presents numerical tests and comparisons of a few recently developed control methods. The testing is conducted using a numerical simulator that simulates a hydraulic PTO. The PTO imposes constraints on the maximum attainable control force and maximum stroke. In addition, the PTO has its own dynamics, which may impact the performance of some control strategies.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-02
      DOI: 10.3390/jmse6020031
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 32: Basic Heat Exchanger Performance Evaluation Method
           on OTEC

    • Authors: Takeshi Yasunaga, Takafumi Noguchi, Takafumi Morisaki, Yasuyuki Ikegami
      First page: 32
      Abstract: Ocean thermal energy conversion (OTEC) harvests the power from the thermal energy in the ocean, which is reserved in the ocean as the temperature difference between warm surface and cold deep seawaters. In the energy conversion, the heat exchangers transfer the thermal energy to the heat engine, which converts it into power. The pressure drops yielded by piping, valve and heat exchangers cause pump loads, which show significant negative power with respect to net power in OTEC. The heat transfer performance and the pressure drop in heat exchanger depend on the types and shapes of each heat transfer area. Generally, heat exchangers with higher friction factors yield higher heat transfer performance and vice versa. However, heat transfer performance and pressure drop are separately evaluated and there is no comprehensive performance evaluation index for OTEC power take-off. Therefore, this research proposes a new simplified overall performance evaluation method for heat exchangers, which can be comprehensively and easily applied and takes into consideration the heat transfer performance and the pressure drop. The evaluation results on plate-type heat exchangers show that the overall performance in each heat exchanger are elucidated and are quantitatively compared.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-03
      DOI: 10.3390/jmse6020032
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 33: In Vitro Inhibition of Acetylcholinesterase,
           Alphaglucosidase, and Xanthine Oxidase by Bacteria Extracts from Coral
           Reef in Hainan, South China Sea

    • Authors: Lin Tan, Suxia Guo, Funing Ma, Chen Chang, Isabel Gómez-Betancur
      First page: 33
      Abstract: Acetylcholinesterase is one of the most important enzymes in living organisms, which is responsible for the synapse cholinergic and other nervous processes. However, its inhibiting effects have proven to have pharmacological applications in the treatment of different diseases, as well as in the control of insect pests; thus, the search for inhibitors is a matter of interest for biomedical and agrochemical fields. Alzheimer’s is a progressive neurodegenerative disease, which can be seen as a wide degeneration of synapses, as well as neurons, in the cerebral cortex, hippocampus, and subcortical structures. Acetylcholinesterase inhibition is an important target for the management of Alzheimer’s. Additionally, diabetes mellitus is a chronic disease with clinical manifestation of hyperglycemia, due to the ineffective production of insulin that controls the level of blood glucose. Alphaglucosidaseinhibitors could retard the uptake of dietary carbohydrates and have shown significant therapeutic effects in clinical application. Fifty-five ethyl acetate extracts from nine bacterial families from Hainan (China) were evaluated to observe their acetylcholinesterase, alphaglucosidase, and xanthine oxidase inhibitory activity. Moreover, a screening of inhibitory activity against the pathogens fungi Fusarium oxysporum and Colletotrichum gloeosporioides was performed. The best acetylcholinesterase and alphaglucosidase inhibitory activity was shown by Vibrio neocaledonicus (98.95%). This is the first report of inhibition of both enzymes by ethyl acetate extract from this strain.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-05
      DOI: 10.3390/jmse6020033
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 34: Nominal vs. Effective Wake Fields and Their
           Influence on Propeller Cavitation Performance

    • Authors: Pelle Regener, Yasaman Mirsadraee, Poul Andersen
      First page: 34
      Abstract: Propeller designers often need to base their design on the nominal model scale wake distribution because the effective full scale distribution is not available. The effects of such incomplete design data on cavitation performance are examined in this paper. The behind-ship cavitation performance of two propellers is evaluated, where the cases considered include propellers operating in the nominal model and full scale wake distributions and in the effective wake distribution, also in the model and full scale. The method for the analyses is a combination of RANS for the ship hull and a panel method for the propeller flow, with a coupling of the two for the interaction of ship and propeller flows. The effect on sheet cavitation due to the different wake distributions is examined for a typical full-form ship. Results show considerable differences in cavitation extent, volume, and hull pressure pulses.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-05
      DOI: 10.3390/jmse6020034
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 35: Simulating Storm Surge Impacts with a Coupled
           Atmosphere-Inundation Model with Varying Meteorological Forcing

    • Authors: Alexandra N. Ramos Valle, Enrique N. Curchitser, Cindy L. Bruyere, Kathryn R. Fossell
      First page: 35
      Abstract: Storm surge events have the potential to cause devastating damage to coastal communities. The magnitude of their impacts highlights the need for increased accuracy and real-time forecasting and predictability of storm surge. In this study, we assess two meteorological forcing configurations to hindcast the storm surge of Hurricane Sandy, and ultimately support the improvement of storm surge forecasts. The Weather Research and Forecasting (WRF) model is coupled to the ADvanced CIRCulation Model (ADCIRC) to determine water elevations. We perform four coupled simulations and compare storm surge estimates resulting from the use of a parametric vortex model and a full-physics atmospheric model. One simulation is forced with track-based meteorological data calculated from WRF, while three simulations are forced with the full wind and pressure field outputs from WRF simulations of varying resolutions. Experiments were compared to an ADCIRC simulation forced by National Hurricane Center best track data, as well as to station observations. Our results indicated that given accurate meteorological best track data, a parametric vortex model can accurately forecast maximum water elevations, improving upon the use of a full-physics coupled atmospheric-surge model. In the absence of a best track, atmospheric forcing in the form of full wind and pressure field from a high-resolution atmospheric model simulation prove reliable for storm surge forecasting.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-05
      DOI: 10.3390/jmse6020035
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 36: Description and Mechanisms of the Mid-Year
           Upwelling in the Southern Caribbean Sea from Remote Sensing and Local Data
           

    • Authors: Digna Rueda-Roa, Tal Ezer, Frank Muller-Karger
      First page: 36
      Abstract: The southern Caribbean Sea experiences strong coastal upwelling between December and April due to the seasonal strengthening of the trade winds. A second upwelling was recently detected in the southeastern Caribbean during June–August, when local coastal wind intensities weaken. Using synoptic satellite measurements and in situ data, this mid-year upwelling was characterized in terms of surface and subsurface temperature structures, and its mechanisms were explored. The mid-year upwelling lasts 6–9 weeks with satellite sea surface temperature (SST) ~1–2° C warmer than the primary upwelling. Three possible upwelling mechanisms were analyzed: cross-shore Ekman transport (csET) due to alongshore winds, wind curl (Ekman pumping/suction) due to wind spatial gradients, and dynamic uplift caused by variations in the strength/position of the Caribbean Current. These parameters were derived from satellite wind and altimeter observations. The principal and the mid-year upwelling were driven primarily by csET (78–86%). However, SST had similar or better correlations with the Ekman pumping/suction integrated up to 100 km offshore (WE100) than with csET, possibly due to its influence on the isopycnal depth of the source waters for the coastal upwelling. The mid-year upwelling was not caused by dynamic uplift but it might have been enhanced by the seasonal intensification of the Caribbean Current during that period.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-05
      DOI: 10.3390/jmse6020036
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 37: Numerical Analysis of Azimuth Propulsor
           Performance in Seaways: Influence of Oblique Inflow and Free Surface

    • Authors: Nabila Berchiche, Vladimir I. Krasilnikov, Kourosh Koushan
      First page: 37
      Abstract: In the present work, a generic ducted azimuth propulsor, which are frequently installed on a wide range of vessels, is subject to numerical investigation with the primary focus on performance deterioration and dynamic loads arising from the influence of oblique inflow and the presence of free surface. An unsteady Reynolds-Averaged Navier-Stokes (RANS) method with the interface Sliding Mesh technique is employed to resolve interaction between the propulsor components. The VOF formulation is used to resolve the presence of free surface. Numerical simulations are performed, separately, in single-phase fluid to address the influence of oblique inflow on the characteristics of a propulsor operating in free-sailing, trawling and bollard conditions, and in multi-phase flow to address the influence of propulsor submergence. Detailed comparisons with experimental data are presented for the case of a propulsor in oblique flow conditions, including integral propulsor characteristics, loads on propulsor components and single blade loads. The results of the study illustrate the differences in propulsor performance at positive and negative heading angles, reveal the frequencies of dynamic load peaks, and provide quantification of thrust losses due to the effect of a free surface without waves. The mechanisms of ventilation inception found at different propulsor loading conditions are discussed.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-05
      DOI: 10.3390/jmse6020037
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 38: Peridynamic Analysis of Marine Composites under
           Shock Loads by Considering Thermomechanical Coupling Effects

    • Authors: Yan Gao, Selda Oterkus
      First page: 38
      Abstract: Nowadays, composite materials have been increasingly used in marine structures because of their high performance properties. During their service time, they may be exposed to extreme loading conditions such as underwater explosions. Temperature changes induced by pure mechanical shock loadings cannot to be neglected especially when smart composite materials are employed for condition monitoring of critical systems in a marine structure. Considering this fact, both the thermal loading effect on deformation and the deformation effect on temperature need to be taken into consideration. Consequently, an analysis conducted in a fully coupled thermomechanical manner is necessary. Peridynamics is a newly proposed non-local theory which can predict failures without extra assumptions. Therefore, a fully coupled thermomechanical peridynamic model is developed for laminated composites materials. In this study, numerical analysis of a 13 ply laminated composite subjected to an underwater explosion is conducted by using the developed model. The pressure shocks generated by the underwater explosion are applied on the top surface of the laminate for uniform and non-uniform load distributions. The damage is predicted and compared with existing experimental results. The simulation results obtained from uncoupled case are also provided for comparison. Thus the coupling term effects on crack propagation paths are investigated. Furthermore, the corresponding temperature distributions are also investigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-06
      DOI: 10.3390/jmse6020038
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 39: Deployment and Maintenance of Wave Energy
           Converters at the Lysekil Research Site: A Comparative Study on the Use of
           Divers and Remotely-Operated Vehicles

    • Authors: Flore Rémouit, Maria-Angeliki Chatzigiannakou, Anke Bender, Irina Temiz, Jan Sundberg, Jens Engström
      First page: 39
      Abstract: Ocean renewable technologies have been rapidly developing over the past years. However, current high installation, operation, maintenance, and decommissioning costs are hindering these offshore technologies to reach a commercialization stage. In this paper we focus on the use of divers and remotely-operated vehicles during the installation and monitoring phase of wave energy converters. Methods and results are based on the wave energy converter system developed by Uppsala University, and our experience in offshore deployments obtained during the past eleven years. The complexity of underwater operations, carried out by either divers or remotely-operated vehicles, is emphasized. Three methods for the deployment of wave energy converters are economically and technically analyzed and compared: one using divers alone, a fully-automated approach using remotely-operated vehicles, and an intermediate approach, involving both divers and underwater vehicles. The monitoring of wave energy converters by robots is also studied, both in terms of costs and technical challenges. The results show that choosing an autonomous deployment method is more advantageous than a diver-assisted method in terms of operational time, but that numerous factors prevent the wide application of robotized operations. Technical solutions are presented to enable the use of remotely-operated vehicles instead of divers in ocean renewable technology operations. Economically, it is more efficient to use divers than autonomous vehicles for the deployment of six or fewer wave energy converters. From seven devices, remotely-operated vehicles become advantageous.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-12
      DOI: 10.3390/jmse6020039
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 40: Fault-Tolerant Control for ROVs Using Control
           Reallocation and Power Isolation

    • Authors: Romano Capocci, Edin Omerdic, Gerard Dooly, Daniel Toal
      First page: 40
      Abstract: This paper describes a novel thruster fault-tolerant control system (FTC) for open-frame remotely operated vehicles (ROVs). The proposed FTC consists of two subsystems: a model-free thruster fault detection and isolation subsystem (FDI) and a fault accommodation subsystem (FA). The FDI subsystem employs fault detection units (FDUs), associated with each thruster, to monitor their state. The robust, reliable and adaptive FDUs use a model-free pattern recognition neural network (PRNN) to detect internal and external faulty states of the thrusters in real time. The FA subsystem combines information provided by the FDI subsystem with predefined, user-configurable actions to accommodate partial and total faults and to perform an appropriate control reallocation. Software-level actions include penalisation of faulty thrusters in solution of control allocation problem and reallocation of control energy among the operable thrusters. Hardware-level actions include power isolation of faulty thrusters (total faults only) such that the entire ROV power system is not compromised. The proposed FTC system is implemented as a LabVIEW virtual instrument (VI) and evaluated in virtual (simulated) and real-world environments. The proposed FTC module can be used for open frame ROVs with up to 12 thrusters: eight horizontal thrusters configured in two horizontal layers of four thrusters each, and four vertical thrusters configured in one vertical layer. Results from both environments show that the ROV control system, enhanced with the FDI and FA subsystems, is capable of maintaining full 6 DOF control of the ROV in the presence of up to 6 simultaneous total faults in the thrusters. With the FDI and FA subsystems in place the control energy distribution of the healthy thrusters is optimised so that the ROV can still operate in difficult conditions under fault scenarios.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-12
      DOI: 10.3390/jmse6020040
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 41: Modelling a Propeller Using Force and Mass Rate
           Density Fields

    • Authors: David Hally
      First page: 41
      Abstract: A method to replace a propeller by force and mass rate density fields has been developed. The force of the propeller on the flow is calculated using a boundary element method (BEM) program and used to generate the force and mass rate fields in a Reynolds-averaged Navier–Stokes (RANS) solver. The procedures to calculate the fields and to allocate them to the cells of a RANS grid are described in detail. The method has been implemented using the BEM program PROCAL and the RANS solver OpenFOAM and tested using the propeller DTMB P4384 operating in open water. Close to the design advance coefficient, the time-average flow fields generated by PROCAL and by OpenFOAM with the force and mass rate fields match to within 1.5% of the inflow speed over almost all of the flow field, including the swept volume of the blades. At two-thirds of the design advance coefficient, the match is about 4% of the inflow speed. The sensitivity of the method to several of its free parameters is investigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-12
      DOI: 10.3390/jmse6020041
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 42: Photogrammetric Surveys and Geometric Processes to
           Analyse and Monitor Red Coral Colonies

    • Authors: Jean-Philip Royer, Mohamad Nawaf, Djamal Merad, Mauro Saccone, Olivier Bianchimani, Joaquim Garrabou, Jean-Baptiste Ledoux, Angel Lopez-Sanz, Pierre Drap
      First page: 42
      Abstract: This article describes the set of photogrammetric tools developed for the monitoring of Mediterranean red coral Corallium rubrum populations. The description encompasses the full processing chain: from the image acquisition to the information extraction and data interpretation. The methods applied take advantage of existing tools and new, innovative and specific developments in order to acquire data on relevant ecological information concerning the structure and functioning of a red coral population. The tools presented here are based on: (i) automatic orientation using coded quadrats; (ii) use of non-photorealistic rendering (NPR) and 3D skeletonization techniques; (iii) computation of distances between colonies from a same site; and (iv) the use of a plenoptic approach in an underwater environment.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-12
      DOI: 10.3390/jmse6020042
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 43: Coupling Numerical Methods and Analytical Models
           for Ducted Turbines to Evaluate Designs

    • Authors: Bradford Knight, Robert Freda, Yin Lu Young, Kevin Maki
      First page: 43
      Abstract: Hydrokinetic turbines extract energy from currents in oceans, rivers, and streams. Ducts can be used to accelerate the flow across the turbine to improve performance. The objective of this work is to couple an analytical model with a Reynolds averaged Navier–Stokes (RANS) computational fluid dynamics (CFD) solver to evaluate designs. An analytical model is derived for ducted turbines. A steady-state moving reference frame solver is used to analyze both the freestream and ducted turbine. A sliding mesh solver is examined for the freestream turbine. An efficient duct is introduced to accelerate the flow at the turbine. Since the turbine is optimized for operation in the freestream and not within the duct, there is a decrease in efficiency due to duct-turbine interaction. Despite the decrease in efficiency, the power extracted by the turbine is increased. The analytical model under-predicts the flow rejection from the duct that is predicted by CFD since the CFD predicts separation but the analytical model does not. Once the mass flow rate is corrected, the model can be used as a design tool to evaluate how the turbine-duct pair reduces mass flow efficiency. To better understand this phenomenon, the turbine is also analyzed within a tube with the analytical model and CFD. The analytical model shows that the duct’s mass flow efficiency reduces as a function of loading, showing that the system will be more efficient when lightly loaded. Using the conclusions of the analytical model, a more efficient ducted turbine system is designed. The turbine is pitched more heavily and the twist profile is adapted to the radial throat velocity profile.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-16
      DOI: 10.3390/jmse6020043
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 44: Residence Time of a Highly Urbanized Estuary:
           Jamaica Bay, New York

    • Authors: Reza Marsooli, Philip M. Orton, James Fitzpatrick, Heather Smith
      First page: 44
      Abstract: Using a validated coupled hydrodynamic-tracer transport model, this study quantified the mean residence time in Jamaica Bay, a highly eutrophic lagoonal estuary in New York City. The Bay is a well-mixed to partially-stratified estuary with heavily-dredged bathymetry and substantial wastewater treatment plant effluent inputs that lead to seasonal hypoxia in some poorly-flushed deep-water basins. Residence time was computed for Jamaica Bay and its largest isolated deep basin, Grassy Bay. The response of residence time to freshwater discharge and wind forcing during summer 2015 was also investigated. The model results showed that the mean residence time, which represents the time required to flush out 63% of tracers released into the region of interest, was 17.9 days in Jamaica Bay and 10.7 days in Grassy Bay. The results also showed that some regions in Jamaica Bay retained their tracers much longer than the calculated residence time and, thus, are potentially prone to water quality problems. Model experiments demonstrated that summertime wind forcing caused a small increase in residence time, whereas freshwater discharge substantially reduced residence time. Freshwater inputs were shown to strongly enhance the two-layer estuarine gravitational circulation and vertical shear, which likely reduced residence time by enhancing shear dispersion. Due to the Bay’s small, highly-urbanized watershed, freshwater inputs are largely derived from the municipal water supply, which is fairly uniform year-round. This water helps to promote bay flushing, yet also carries a high nitrogen load from wastewater treatment. Lastly, the tidal prism method was used to create a simple calibrated model of residence time using the geometry of the study area and the tidal range and period.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-20
      DOI: 10.3390/jmse6020044
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 45: Experimental and Numerical Investigation of
           Propeller Loads in Off-Design Conditions

    • Authors: Fabrizio Ortolani, Giulio Dubbioso, Roberto Muscari, Salvatore Mauro, Andrea Di Mascio
      First page: 45
      Abstract: The understanding of the performance of a propeller in realistic operative conditions is nowadays a key issue for improving design techniques, guaranteeing safety and continuity of operation at sea, and reducing maintenance costs. In this paper, a summary of the recent research carried out at CNR-INSEAN devoted to the analysis of propeller loads in realistic operative scenarios, with particular emphasis on the in-plane loads, is presented. In particular, the experimental results carried out on a free running maneuvering model equipped with a novel force transducer are discussed and supported by C F D (Computational Fluid Dynamics) analysis and the use of a simplified propeller model, based on Blade Element Momentum Theory, with the aim of achieving a deeper understanding of the mechanisms that govern the functioning of the propeller in off-design. Moreover, the analysis includes the scaling factors that can be used to obtain a prediction from model measurements, the propeller radial force being the primary cause of failures of the shaft bearings. In particular, the analysis highlighted that cavitation at full scale can cause the increment of in-plane loads by about 20% with respect to a non-cavitating case, that that in-plane loads could be more sensitive to cavitation than thrust and torque, and that Reynolds number effect is negligible. For the analysis of cavitation, an alternative version of the B E M T solver, improved with cavitation linear theory, was developed.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-04-24
      DOI: 10.3390/jmse6020045
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 46: Influence of Propulsion Type on the Stratified
           Near Wake of an Axisymmetric Self-Propelled Body

    • Authors: Matthew C. Jones, Eric G. Paterson
      First page: 46
      Abstract: To better understand the influence of swirl on the thermally-stratified near wake of a self-propelled axisymmetric vehicle, three propulsor schemes were considered: a single propeller, contra-rotating propellers (CRP), and a zero-swirl, uniform-velocity jet. The propellers were modeled using an Actuator-Line model in an unsteady Reynolds-Averaged Navier–Stokes simulation, where the Reynolds number is R e L = 3.1 × 10 8 using the freestream velocity and body length. The authors previously showed good comparison to experimental data with this approach. Visualization of vortical structures shows the helical paths of blade-tip vortices from the single propeller as well as the complicated vortical interaction between contra-rotating blades. Comparison of instantaneous and time-averaged fields shows that temporally stationary fields emerge by half of a body length downstream. Circumferentially-averaged axial velocity profiles show similarities between the single propeller and CRP in contrast to the jet configuration. Swirl velocity of the CRP, however, was attenuated in comparison to that of the single propeller case. Mixed-patch contour maps illustrate the unique temperature distribution of each configuration as a consequence of their respective swirl profiles. Finally, kinetic and potential energy is integrated along downstream axial planes to reveal key differences between the configurations. The CRP configuration creates less potential energy by reducing swirl that would otherwise persist in the near wake of a single-propeller wake.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-01
      DOI: 10.3390/jmse6020046
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 47: Using Live-Stream Video from an Artificial Reef to
           Increase Interest in Marine Biology

    • Authors: Lars Seidelin, Magnus Wahlberg, Marianne Holmer
      First page: 47
      Abstract: New methods are needed to attract more interest to natural sciences among the public and young people. We established an underwater laboratory by placing cameras on an artificial reef (a sunken ferry) to create a new and inspiring way of teaching marine biology and showing science to the public. Here we describe the process and solutions to the technical challenges in designing the laboratory. Live-streaming from the underwater environment has great potential for teaching marine biology in new and exciting ways, and it could also be used more widely for stimulating interest among the general public in aquariums and museums.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-01
      DOI: 10.3390/jmse6020047
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 48: Probabilistic Assessment of Overtopping of Sea
           Dikes with Foreshores including Infragravity Waves and Morphological
           Changes: Westkapelle Case Study

    • Authors: Patrick Oosterlo, Robert Timothy McCall, Vincent Vuik, Bas Hofland, Jentsje Wouter van der Meer, Sebastiaan Nicolaas Jonkman
      First page: 48
      Abstract: Shallow foreshores in front of coastal dikes can reduce the probability of dike failure due to wave overtopping. A probabilistic model framework is presented, which is capable of including complex hydrodynamics like infragravity waves, and morphological changes of a sandy foreshore during severe storms in the calculations of the probability of dike failure due to wave overtopping. The method is applied to a test case based on the Westkapelle sea defence in The Netherlands, a hybrid defence consisting of a dike with a sandy foreshore. The model framework consists of the process-based hydrological and morphological model XBeach, probabilistic overtopping equations (EurOtop) and the level III fully probabilistic method ADIS. By using the fully probabilistic level III method ADIS, the number of simulations necessary is greatly reduced, which allows for the use of more advanced and detailed hydro- and morphodynamic models. The framework is able to compute the probability of failure with up to 15 stochastic variables and is able to describe feasible physical processes. Furthermore, the framework is completely modular, which means that any model or equation can be plugged into the framework, whenever updated models with improved representation of the physics or increases in computational power become available. The model framework as described in this paper, includes more physical processes and stochastic variables in the determination of the probability of dike failure due to wave overtopping, compared to the currently used methods in The Netherlands. For the here considered case, the complex hydrodynamics like infragravity waves and wave set-up need to be included in the calculations, because they appeared to have a large influence on the probability of failure. Morphological changes of the foreshore during a severe storm appeared to have less influence on the probability of failure for this case. It is recommended to apply the framework to other cases as well, to determine if the effects of complex hydrodynamics as infragravity waves and morphological changes on the probability of sea dike failure due to wave overtopping as found in this paper hold for other cases as well. Furthermore, it is recommended to investigate broader use of the method, e.g., for safety assessment, reliability analysis and design.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-01
      DOI: 10.3390/jmse6020048
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 49: A Semi-Empirical Prediction Method for Broadband
           Hull-Pressure Fluctuations and Underwater Radiated Noise by Propeller Tip
           Vortex Cavitation †

    • Authors: Johan Bosschers
      First page: 49
      Abstract: A semi-empirical method is presented that predicts broadband hull-pressure fluctuations and underwater radiated noise due to propeller tip vortex cavitation. The method uses a hump-shaped pattern for the spectrum and predicts the centre frequency and level of this hump. The principal parameter is the vortex cavity size, which is predicted by a combination of a boundary element method and a semi-empirical vortex model. It is shown that such a model is capable of representing the variation of cavity size with cavitation number well. Using a database of model- and full-scale measured hull-pressure data, an empirical formulation for the maximum level and centre frequency has been developed that is a function of, among other parameters, the cavity size. Acceptable results are obtained when comparing predicted and measured hull-pressure and radiated noise spectra for various cases. The comparison also shows differences that require adjustments of parameters that need to be further investigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-02
      DOI: 10.3390/jmse6020049
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 50: Experimental Investigation of Propeller Wake
           Velocity Field to Determine the Major Factors Affecting Propeller Wake
           Wash

    • Authors: Md. Amin, Bruce Colbourne, Brian Veitch
      First page: 50
      Abstract: The propeller jet from a ship has a significant component directed upwards towards the free surface of the water, which can be used for ice management. This paper describes a comprehensive laboratory experiment where the operational factors affecting a propeller wake velocity field were investigated. The experiment was conducted using a steady wake field to investigate the characteristics of the axial velocity of the fluid in the wake and the corresponding variability downstream of the propeller. The axial velocities and the variability recorded were time-averaged. Propeller rotational speed was found to be the most significant factor, followed by propeller inclination. The experimental results also provide some idea about the change of the patterns of the mean axial velocity distribution against the factors considered for the test throughout the effective wake field, as well as the relationships to predict the axial velocity for known factors.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-07
      DOI: 10.3390/jmse6020050
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 51: Experimental Validation of Fluid–Structure
           Interaction Computations of Flexible Composite Propellers in Open Water
           Conditions Using BEM-FEM and RANS-FEM Methods

    • Authors: Pieter Maljaars, Laurette Bronswijk, Jaap Windt, Nicola Grasso, Mirek Kaminski
      First page: 51
      Abstract: In the past several decades, many papers have been published on fluid–structure coupled calculations to analyse the hydro-elastic response of flexible (composite) propellers. The flow is usually modelled either by the Navier–Stokes equations or as a potential flow, by assuming an irrotational flow. Phenomena as separation of the flow, flow transition, boundary layer build-up and vorticity dynamics are not captured in a non-viscous potential flow. Nevertheless, potential flow based methods have been shown to be powerful methods to resolve the hydrodynamics of propellers. With the upcoming interest in flexible (composite) propellers, a valid question is what the consequences of the potential flow simplifications are with regard to the coupled fluid–structure analyses of these types of propellers. This question has been addressed in the following way: calculations and experiments were conducted for uniform flows only, with a propeller geometry that challenges the potential flow model due to its sensitivity to leading edge vortex separation. Calculations were performed on the undeformed propeller geometry with a Reynolds-averaged-Navier–Stokes (RANS) solver and a boundary element method (BEM). These calculations show some typical differences between the RANS and BEM results. The flexible propeller responses were predicted by coupled calculations between BEM and finite element method (FEM) and RANS and FEM. The applied methodologies are briefly described. Results obtained from both calculation methods have been compared to experimental results obtained from blade deformation measurements in a cavitation tunnel. The results show that, even for the extreme cases, promising results have been obtained with the BEM-FEM coupling. The BEM-FEM calculated responses are consistent with the RANS-FEM results.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-07
      DOI: 10.3390/jmse6020051
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 52: Prediction of Propeller-Induced Hull Pressure
           Fluctuations via a Potential-Based Method: Study of the Effects of
           Different Wake Alignment Methods and of the Rudder

    • Authors: Yiran Su, Seungnam Kim, Spyros A. Kinnas
      First page: 52
      Abstract: In order to predict ship hull pressure fluctuations induced by marine propellers, a combination of several numerical schemes is used. The propeller perturbation flow is solved by the boundary element method (BEM), while the coupling between a BEM solver and a Reynolds-averaged Navier-Stokes (RANS) solver can efficiently predict the effective wake. Based on the BEM solution under the predicted effective wake, the propeller-induced potential on the ship hull can be evaluated. Then, a pressure-BEM solver is used to solve the diffraction pressure on the hull in order to obtain the solid boundary factor which leads to the total hull pressure. This paper briefly introduces the schemes and numerical models. To avoid numerical instability, several simplifications need to be made. The effects of these simplifications are studied, including the rudder effect and the wake alignment model effect.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-08
      DOI: 10.3390/jmse6020052
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 53: Marine Turbine Hydrodynamics by a Boundary Element
           Method with Viscous Flow Correction

    • Authors: Francesco Salvatore, Zohreh Sarichloo, Danilo Calcagni
      First page: 53
      Abstract: A computational methodology for the hydrodynamic analysis of horizontal axis marine current turbines is presented. The approach is based on a boundary integral equation method for inviscid flows originally developed for marine propellers and adapted here to describe the flow features that characterize hydrokinetic turbines. For this purpose, semi-analytical trailing wake and viscous flow correction models are introduced. A validation study is performed by comparing hydrodynamic performance predictions with two experimental test cases and with results from other numerical models in the literature. The capability of the proposed methodology to correctly describe turbine thrust and power over a wide range of operating conditions is discussed. Viscosity effects associated to blade flow separation and stall are taken into account and predicted thrust and power are comparable with results of blade element methods that are largely used in the design of marine current turbines. The accuracy of numerical predictions tends to reduce in cases where turbine blades operate in off-design conditions.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-08
      DOI: 10.3390/jmse6020053
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 54: Storm Surge and Wave Impact of Low-Probability
           Hurricanes on the Lower Delaware Bay—Calibration and Application

    • Authors: Mehrdad Salehi
      First page: 54
      Abstract: Hurricanes pose major threats to coastal communities and sensitive infrastructure, including nuclear power plants, located in the vicinity of hurricane-prone coastal regions. This study focuses on evaluating the storm surge and wave impact of low-probability hurricanes on the lower Delaware Bay using the Delft3D dynamically coupled wave and flow model. The model comprised Overall and Nested domains. The Overall model domain encompassed portions of the Atlantic Ocean, Delaware Bay, and Chesapeake Bay. The two-level Nested model domains encompassed the Delaware Estuary, its floodplain, and a portion of the continental shelf. Low-probability hurricanes are critical considerations in designing and licensing of new nuclear power plants as well as in establishing mitigating strategies for existing power facilities and other infrastructure types. The philosophy behind low-probability hurricane modeling is to establish reasonable water surface elevation and wave characteristics that have very low to no probability of being exceeded in the region. The area of interest (AOI) is located on the west bank of Delaware Bay, almost 16 miles upstream of its mouth. The model was first calibrated for Hurricane Isabel (2003) and then applied to synthetic hurricanes with very low probability of occurrence to establish the storm surge envelope at the AOI. The model calibration results agreed reasonably well with field observations of water surface elevation, wind velocity, wave height, and wave period. A range of meteorological, storm track direction, and storm bearing parameters that produce the highest sustained wind speeds were estimated using the National Weather Service (NWS) methodology and applied to the model. Simulations resulted in a maximum stillwater elevation and wave height of 7.5 m NAVD88 and 2.5 m, respectively, at the AOI. Comparison of results with the U.S. Army Corps of Engineers, North Atlantic Coastal Comprehensive Study (USACE-NACCS) storm surge values at the AOI demonstrates that the estimated elevation has an annual exceedance probability of less than 10 − 4 .
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-10
      DOI: 10.3390/jmse6020054
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 55: An Effective Modelling Approach to Support
           Probabilistic Flood Forecasting in Coastal Cities—Case Study: Can Tho,
           Mekong Delta, Vietnam

    • Authors: Hieu Ngo, Assela Pathirana, Chris Zevenbergen, Roshanka Ranasinghe
      First page: 55
      Abstract: Probabilistic flood forecasting requires flood models that are simple and fast. Many of the modelling applications in the literature tend to be complex and slow, making them unsuitable for probabilistic applications which require thousands of individual simulations. This article focusses on the development of such a modelling approach to support probabilistic assessment of flood hazards, while accounting for forcing and system uncertainty. Here, we demonstrate the feasibility of using the open-source SWMM (Storm Water Management Model), focussing on Can Tho city, Mekong Delta, Vietnam. SWMM is a dynamic rainfall-runoff simulation model which is generally used for single event or long-term (continuous) simulation of runoff quantity and quality and its application for probabilistic riverflow modelling is atypical. In this study, a detailed SWMM model of the entire Mekong Delta was built based on an existing ISIS model containing 575 nodes and 592 links of the same study area. The detailed SWMM model was then systematically reduced by strategically removing nodes and links to eventually arrive at a level of detail that provides sufficiently accurate predictions of water levels for Can Tho for the purpose of simulating urban flooding, which is the target diagnostic of this study. After a comprehensive assessment (based on trials with the varying levels of complexity), a much reduced SWMM model comprising 37 nodes and 40 links was determined to be able to provide a sufficiently accurate result while being fast enough to support probabilistic future flood forecasting and, further, to support flood risk reduction management.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-11
      DOI: 10.3390/jmse6020055
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 56: DDES of Wetted and Cavitating Marine Propeller for
           CHA Underwater Noise Assessment

    • Authors: Ville M. Viitanen, Antti Hynninen, Tuomas Sipilä, Timo Siikonen
      First page: 56
      Abstract: In this paper we present results of delayed detached eddy simulation (DDES) and computational hydroacoustics (CHA) simulations of a marine propeller operating in a cavitation tunnel. DDES is carried out in both wetted and cavitating conditions, and we perform the investigation at several propeller loadings. CHA analyses are done for one propeller loading both in wetted and cavitating conditions. The simulations are validated against experiments conducted in the cavitation tunnel. Propeller global forces, local flow phenomena, as well as cavitation patterns are compared to the cavitation tunnel tests. Hydroacoustic sources due to the propeller are evaluated from the flow solution, and corresponding acoustic simulations utilizing an acoustic analogy are made. The propeller wake flow structures are investigated for the wetted and cavitating operating conditions, and the acoustic excitation and output of the same cases are discussed.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-21
      DOI: 10.3390/jmse6020056
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 57: Announcing the 2018 JMSE Travel Awards for
           Postdoctoral Researchers and Ph.D. Students

    • Authors: Anthony S. Clare
      First page: 57
      Abstract: n/a
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-22
      DOI: 10.3390/jmse6020057
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 58: Using Coupled Hydrodynamic Biogeochemical Models
           to Predict the Effects of Tidal Turbine Arrays on Phytoplankton Dynamics

    • Authors: Pia Schuchert, Louise Kregting, Daniel Pritchard, Graham Savidge, Björn Elsäßer
      First page: 58
      Abstract: The effects of large scale tidal energy device (TED) arrays on phytoplankton processes owing to the changes in hydrodynamic flows are unknown. Coupled two-dimensional biogeochemical and hydrodynamic models offer the opportunity to predict potential effects of large scale TED arrays on the local and regional phytoplankton dynamics in coastal and inshore environments. Using MIKE 21 Software by DHI (https://www.dhigroup.com), coupled two-dimensional biogeochemical and hydrodynamic models were developed with simulations including no turbines or an array of 55 turbines with four solar radiation scenarios to assess the temporal and spatial changes of phytoplankton dynamics in an idealised domain. Results suggest that the effect of TEDs on phytoplankton dynamics accounted for up to 25% of the variability in phytoplankton concentrations, most likely associated with an increased residence time in an inshore basin. However, natural variation, such as the intensity of photosynthetically active radiation, had a larger effect on phytoplankton dynamics than an array of TEDs.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-22
      DOI: 10.3390/jmse6020058
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 59: Projected 21st Century Coastal Flooding in the
           Southern California Bight. Part 1: Development of the Third Generation
           CoSMoS Model

    • Authors: Andrea C. O’Neill, Li H. Erikson, Patrick L. Barnard, Patrick W. Limber, Sean Vitousek, Jonathan A. Warrick, Amy C. Foxgrover, Jessica Lovering
      First page: 59
      Abstract: Due to the effects of climate change over the course of the next century, the combination of rising sea levels, severe storms, and coastal change will threaten the sustainability of coastal communities, development, and ecosystems as we know them today. To clearly identify coastal vulnerabilities and develop appropriate adaptation strategies due to projected increased levels of coastal flooding and erosion, coastal managers need local-scale hazards projections using the best available climate and coastal science. In collaboration with leading scientists world-wide, the USGS designed the Coastal Storm Modeling System (CoSMoS) to assess the coastal impacts of climate change for the California coast, including the combination of sea-level rise, storms, and coastal change. In this project, we directly address the needs of coastal resource managers in Southern California by integrating a vast range of global climate change projections in a thorough and comprehensive numerical modeling framework. In Part 1 of a two-part submission on CoSMoS, methods and the latest improvements are discussed, and an example of hazard projections is presented.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-24
      DOI: 10.3390/jmse6020059
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 60: The Effect of Propeller Scaling Methodology on the
           Performance Prediction

    • Authors: Stephan Helma, Heinrich Streckwall, Jan Richter
      First page: 60
      Abstract: In common model testing practise, the measured values of the self propulsion test are split into the characteristics of the hull, the propeller and into the interaction factors. These coefficients are scaled separately to the respective full scale values and subsequently reassembled to give the power prediction. The accuracy of this power prediction depends inter alia on the accuracy of the measured values and the scaling procedure. An inherent problem of this approach is that it is virtually impossible to verify each single step, because of the complex nature of the underlying problem. In recent years the scaling of the open-water characteristics of propeller model tests attracted a renewed interest, fuelled by competitive tests, which became the norm due to requests of the customer. This paper shows the influence of different scaling procedures on the predicted power. The prediction is compared to the measured trials data and the quality of the prediction is judged. The procedures examined are the standard ITTC 1978 procedure plus derivatives of it, the Meyne method, the strip method developed by the Hamburgische Schiffbau-Versuchsanstalt (HSVA) and the β i -method by Helma.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-24
      DOI: 10.3390/jmse6020060
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 61: Optimal Transmission of Interface Vibration
           Wavelets—A Simulation of Seabed Seismic Responses

    • Authors: Richard A. Hazelwood, Patrick C. Macey, Stephen P. Robinson, Lian S. Wang
      First page: 61
      Abstract: Seismic interface waves generated by seabed impacts are believed to have biological importance. Previous work on the effects of ocean piling and dredging studied water motion adjacent to the seabed, using sediment measurements as reviewed in the literature. This new modelling work has idealised the sediment data to a simple model with few parameters, and has shown how this leads to filtration of the applied energy to propagate simple seismic vibration wavelets. These special wavelets remain compact with high peak levels of the associated water particle velocity as they ripple outward, and provide a means of assessing the worst-case environmental impact. The form of this wavelet morphs from a hump shape to a dip and back, via intermediate forms which are here described in mathematical terms based on the Ricker form. Whilst the model structure is idealised it is much closer to reality than the Rayleigh and Scholte half-space models, but with only two more parameters required. The resultant wavelet peaks are propagated with values given by the optimal limit case of cylindrical spreading (ignoring absorption) which results in a relatively widespread impact.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-05-29
      DOI: 10.3390/jmse6020061
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 62: Implementation of an Implicit Solver in ADCIRC
           Storm Surge Model

    • Authors: Abdullah Alghamdi, Muhammad K. Akbar
      First page: 62
      Abstract: The current state of science does not offer any remedy to stop a hurricane from occurring. Therefore, accurate storm surge models capable of predicting water velocity and elevation are indispensable. In this paper, the implementation of an implicit solver in the Advanced Circulation (ADCIRC) storm surge model is presented. The implemented implicit solver uses hybrid finite element and finite volume techniques for solving shallow water equations. Objectives of this research include: Enhancing numerical stability, providing an option of using large timesteps, and the usage of a relatively easier mathematical formulation than the existing one in ADCIRC. The storm surge hindcast of Hurricane Katrina that hit Louisiana and Mississippi in 2005 is used as a case study. Stability of the solver, comparison of water elevation and velocity against observed data, impact of timestep sizes, and execution times of solvers are thoroughly investigated in this study. Results of the implemented implicit solver are compared with those of existing lumped explicit and semi-implicit solvers of ADCIRC; the findings appear to be very promising.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-01
      DOI: 10.3390/jmse6020062
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 63: The Anticipation of the ENSO: What Resonantly
           Forced Baroclinic Waves Can Teach Us (Part II)

    • Authors: Jean-Louis Pinault
      First page: 63
      Abstract: The purpose of the paper is to take advantage of recent work on the study of resonantly forced baroclinic waves in the tropical Pacific to significantly reduce systematic and random forecasting errors resulting from the current statistical models intended to predict El Niño. Their major drawback is that sea surface temperature (SST), which is widely used, is very difficult to decipher because of the extreme complexity of exchanges at the ocean-atmosphere interface. In contrast, El Niño-Southern Oscillation (ENSO) forecasting can be performed between 7 and 8 months in advance precisely and very simply from (1) the subsurface water temperature at particular locations and (2) the time lag of the events (their expected date of occurrence compared to a regular 4-year cycle). Discrimination of precursor signals from objective criteria prevents the anticipation of wrong events, as occurred in 2012 and 2014. The amplitude of the events, their date of appearance, as well as their potential impact on the involved regions are estimated. Three types of ENSO events characterize their climate impact according to whether they are (1) unlagged or weakly lagged, (2) strongly lagged, or (3) out of phase with the annual quasi-stationary wave (QSW) (Central Pacific El Niño events). This substantial progress is based on the analysis of baroclinic QSWs in the tropical basin and the resulting genesis of ENSO events. As for cold events, the amplification of La Niña can be seen a few months before the maturation phase of an El Niño event, as occurred in 1998 and 2016.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-01
      DOI: 10.3390/jmse6020063
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 64: Coastal Defence Integrating Wave-Energy-Based
           Desalination: A Case Study in Madagascar

    • Authors: Pasquale Contestabile, Diego Vicinanza
      First page: 64
      Abstract: In arid, coastal cities, water demand is often met through large-scale desalination systems. However, the energy required to run desalination plants remains a drawback. Further, numerous low-density population areas lack not only fresh water availability, but in most of the cases electrical grid connection or any other energy source as well. The challenge, consequently, is to ensure adequate fresh water supplies at the lowest possible cost. The main objective of this work is to assess the freshwater production from a reverse osmosis desalination system powered by a wave energy converter, the Overtopping Breakwater for Wave Energy Conversion (OBREC). The desktop analysis is illustrated through a case study on the Fenoarivo Atsinanana coast, along north-eastern Madagascar. The novel aspect of the analysis method is the application of a specific numerical code calibrated using preliminary results from a two-year monitoring campaign of the first OBREC prototype in operation in Naples Harbour (Italy). Instead of dissipating the incoming wave energy, the system collects the overtopping water above the sea level and the potential energy is converted into electricity through low head turbines. Then, the flow will be driven towards the desalination system. This configuration seems like a promising opportunity for developing countries to meet their water supply needs while at the same time developing their renewable energy potential.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-01
      DOI: 10.3390/jmse6020064
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 65: Exchange Flow Variability between Hypersaline
           Shark Bay and the Ocean

    • Authors: Yasha Hetzel, Charitha Pattiaratchi, Hrvoje Mihanović
      First page: 65
      Abstract: In Shark Bay, a large hypersaline bay in Western Australia, longitudinal density gradients force gravitational circulation that is important for Bay-ocean exchange. First-time observations of vertical stratification and velocity are presented, confirming the presence of a steady, near-bed dense water outflow from Shark Bay’s northern Geographe Channel that persisted through all stages of the tide. Outflow velocities were 2–3 times stronger than the outflows recorded previously in Naturaliste Channel (in the west), and were more resistant to breakdown by tidal mixing. Estimates of turbulent kinetic energy production derived from the variance method showed a more complex structure in the Geographe Channel, due to shear between surface and bottom layers. Turbulence varied between flood and ebb tide, with peak levels of turbulence occurring during reversal of tidal flows. For both channels, the main source of turbulence was tidal flow along the seabed, with the bottom current speed cubed, Ub3 , providing a reasonable proxy for tidal mixing and prediction of dense water outflows from Shark Bay majority of the time. Orientation and deeper water of the Geographe Channel along the main axis of the longitudinal density gradient provided an explanation for the predominant outflow from the Bay’s northern entrance. These density-driven currents could potentially influence recruitment of commercially fished scallops and prawns through the dispersal and flushing of larvae.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-01
      DOI: 10.3390/jmse6020065
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 66: Modelling Hydrodynamic Impacts of Sea-Level Rise
           on Wave-Dominated Australian Estuaries with Differing Geomorphology

    • Authors: Kristian Kumbier, Rafael C. Carvalho, Colin D. Woodroffe
      First page: 66
      Abstract: Sea-level rise (SLR) will affect the hydrodynamics and flooding characteristics of estuaries which are a function of the geomorphology of particular estuarine systems. This study presents a numerical modelling of coastal flooding due to drivers such as spring-tides, storm surges and river inflows and examines how these will change under sea-level increases of 0.4 m and 0.9 m for two estuaries that are at different geomorphological evolutionary stages of infill. Our results demonstrate that estuarine response to SLR varies between different types of estuaries, and detailed modelling is necessary to understand the nature and extent of inundation in response to SLR. Comparison of modelling results indicates that floodplain elevation is fundamental in order to identify the most vulnerable systems and estimate how inundation extents and depths may change in the future. Floodplains in mature estuarine systems may drown and experience a considerable increase in inundation depths once a certain threshold in elevation has been exceeded. By contrast, immature estuarine systems may be subject to increases in relative inundation extent and substantial changes in hydrodynamics such as tidal range and current velocity. The unique nature of estuaries does not allow for generalisations; however, classifications of estuarine geomorphology could indicate how certain types of estuary may respond to SLR.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-05
      DOI: 10.3390/jmse6020066
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 67: Boundary Element Modelling Aspects for the
           Hydro-Elastic Analysis of Flexible Marine Propellers

    • Authors: Pieter Maljaars, Mirek Kaminski, Henk den Besten
      First page: 67
      Abstract: Boundary element methods (BEM) have been used for propeller hydrodynamic calculations since the 1990s. More recently, these methods are being used in combination with finite element methods (FEM) in order to calculate flexible propeller fluid–structure interaction (FSI) response. The main advantage of using BEM for flexible propeller FSI calculations is the relatively low computational demand in comparison with higher fidelity methods. However, the BEM modelling of flexible propellers is not straightforward and requires several important modelling decisions. The consequences of such modelling choices depend significantly on propeller structural behaviour and flow condition. The two dimensionless quantities that characterise structural behaviour and flow condition are the structural frequency ratio (the ratio between the lowest excitation frequency and the fundamental wet blade natural frequency) and the reduced frequency. For both, general expressions have been derived for (flexible) marine propellers. This work shows that these expressions can be effectively used to estimate the dry and wet fundamental blade frequencies and the structural frequency ratio. This last parameter and the reduced frequency of vibrating blade flows is independent of the geometrical blade scale as shown in this work. Regarding the BEM-FEM coupled analyses, it is shown that a quasi-static FEM modelling does not suffice, particularly due to the fluid-added mass and hydrodynamic damping contributions that are not negligible. It is demonstrated that approximating the hydro-elastic blade response by using closed form expressions for the fluid added mass and hydrodynamic damping terms provides reasonable results, since the structural response of flexible propellers is stiffness dominated, meaning that the importance of modelling errors in fluid added mass and hydrodynamic damping is small. Finally, it is shown that the significance of recalculating the hydrodynamic influence coefficients is relatively small. This fact might be utilized, possibly in combination with the use of the closed form expressions for fluid added mass and hydrodynamic damping contributions, to significantly reduce the computation time of flexible propeller FSI calculations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-05
      DOI: 10.3390/jmse6020067
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 68: Seiching Induced by Bichromatic and Monochromatic
           Wave Conditions: Experimental and Numerical Analysis in a Large Wave Flume
           

    • Authors: Luigia Riefolo, Pasquale Contestabile, Diego Vicinanza
      First page: 68
      Abstract: This paper describes a set of spectral and eigen analysis in order to identify seiche generation from a large-scale laboratory dataset. The experiments were performed in the large-scale “Canal d’Investigació i Experimentació Marítima” wave flume at the Universitat Politècnica de Catalunya in Spain. Erosive and accretive wave regimes have been analyzed, including monochromatic waves and bichromatic wave groups with different bandwidths. Each test started with approximately the same underlying beach conditions. Video runup measurements are also used to better understand the role of the bandwidth in the generation of swash oscillation. Some evidence of the influence of low frequency waves on runup and sediment transport pattern is found. Good agreements between eigenmode families for volume flux and sediment volume variations are also shown.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-06
      DOI: 10.3390/jmse6020068
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 69: Ballast Water Management in the Black Sea’s
           Ports

    • Authors: Vasile Rata, Carmen Gasparotti, Liliana Rusu
      First page: 69
      Abstract: The objective of this work is to develop a case study in order to improve the ballast water management in the Black Sea’s ports. From this perspective, the present paper provides an extensive explanation about the main issues related to the control of marine non-indigenous species introduction through ballast water discharged by ships during their operations in the ports. Thereafter, it quantifies the amount of the ballast water discharged in the major ports of the Black Sea and the amount of the invading species that could reach these ports. Although, globally speaking, the problem of ballast water management is a reality, only three of the six neighboring countries in the Black Sea basin have signed, in 2004, the ratification of the International Convention on Management of Ships’ Ballast Water and Sediments. This is also known as the Water Ballast Management Convention, and it provides regulations concerning ballast water management generated by the shipping activities through a common set of rules.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-09
      DOI: 10.3390/jmse6020069
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 70: Frequency Analysis of Storm-Surge-Induced Flooding
           for the Huangpu River in Shanghai, China

    • Authors: Qian Ke, Sebastiaan N. Jonkman, Pieter H. A. J. M. van Gelder, Jeremy D. Bricker
      First page: 70
      Abstract: Shanghai, as a coastal city, is vulnerable to various types of flooding. The floodwalls along the Huangpu River provide protection against typhoon-induced flooding. However, there is limited insight into the actual safety level of the flood defences in Shanghai, and recent failures have highlighted their vulnerability. Therefore, the aims of this paper are to derive a series of new flood frequency curves for the Huangpu River, and to evaluate the level of protection of the floodwall system. This paper analysed over 100 years (1912–2013) of annual maximum water levels for three stations at near-sea, mid-stream and inland locations along the Huangpu River. Best-fit curves were determined for a number of selected probability distributions using statistical performance indicators. As a result, new flood frequency curves of the water levels for different storm surge return periods were produced. The results showed that generalised extreme value (GEV) was identified as the most suitable probability distribution for the datasets. Analysis showed that the current design water levels correspond to exceedance probabilities of 1/500 per year at the near-sea and mid-stream stations, and no more than 1/50 per year at the inland station of the Huangpu River, whereas the intended safety standard is 1/1000 per year. A comparison of the findings with a dataset of the crest heights of the floodwalls showed that the current protection level of the floodwalls along the Huangpu River is expected to be around 1/50 per year in terms of overtopping for the lowest sections. The results of this study can be utilized to provide future recommendations for flood risk management in Shanghai.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-11
      DOI: 10.3390/jmse6020070
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 71: Numerical Simulation and Uncertainty Analysis of
           an Axial-Flow Waterjet Pump

    • Authors: Ji-Tao Qiu, Chen-Jun Yang, Xiao-Qian Dong, Zong-Long Wang, Wei Li, Francis Noblesse
      First page: 71
      Abstract: Unsteady Reynolds-averaged Navier–Stokes simulations of an axial-flow pump for waterjet propulsion are carried out at model scale, and the numerical uncertainties are analyzed mainly according to the procedure recommended by the twenty-eighth International Towing Tank Conference. The two-layer realizable k-ε model is adopted for turbulence closure, and the flow in viscous sub-layer is resolved. The governing equations are discretized with second-order schemes in space and first-order scheme in time and solved by the semi-implicit method for pressure-linked equations. The computational domain is discretized into block-structured hexahedral cells. For an axial-flow pump consisting of a seven-bladed rotor and a nine-bladed stator, the uncertainty analysis is conducted by using three sets of successively refined grids and time steps. In terms of the head and power over a range of flow rates, it is verified that the simulation uncertainty is less than 4.3%, and the validation is successfully achieved at an uncertainty level of 4.4% except for the lowest flow rate. Besides this, the simulated flow features around rotor blade tips and between the stator and rotor blade rows are investigated.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-11
      DOI: 10.3390/jmse6020071
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 72: Obtaining Reflection Coefficients from a Single
           Point Velocity Measurement

    • Authors: Rachael McKee, Björn Elsäßer, Pál Schmitt
      First page: 72
      Abstract: The quantification of the reflection of water waves is of paramount importance in coastal and marine engineering. Reflected waves are produced as a result of an incident wave meeting a reflective boundary e.g., in a wave basin. While reflection can be seen as an undesirable disturbance, for example in experimental tests performed in confined tanks, it can also have a useful purpose such as being directed towards wave energy converters (WECs). Whether useful or not, reflection needs to be accurately quantified. For cases effected by directional spreading such as WECs, the wave height of a reflected wave will be spatially variable. The majority of quantification methods are based on frequency domain analysis of surface elevation data at more than one discrete location over approximately one wavelength. Thus, a method which requires a single point measurement is desirable. This paper presents a novel method derived from Linear Wave theory to quantify reflection coefficients using orbital velocity measurements at one discrete location. An additional advantage of this method is it only requires data over a single wave cycle and thus will be particularly suitable for numerical simulations. In the present form the method is only applicable to monochromatic waves. The theoretical background of the method is explained in detail. An application is demonstrated through a comparison to reflections quantified using surface elevation measurements in Computational Fluid Dynamics (CFD) numerical simulations. It is found that the results of the new proposed method compare to surface elevation methods within the levels of experimental accuracy.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-13
      DOI: 10.3390/jmse6020072
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 73: Analysis of Different Methods for Wave Generation
           and Absorption in a CFD-Based Numerical Wave Tank

    • Authors: Adria Moreno Miquel, Arun Kamath, Mayilvahanan Alagan Chella, Renata Archetti, Hans Bihs
      First page: 73
      Abstract: In this paper, the performance of different wave generation and absorption methods in computational fluid dynamics (CFD)-based numerical wave tanks (NWTs) is analyzed. The open-source CFD code REEF3D is used, which solves the Reynolds-averaged Navier–Stokes (RANS) equations to simulate two-phase flow problems. The water surface is computed with the level set method (LSM), and turbulence is modeled with the k-ω model. The NWT includes different methods to generate and absorb waves: the relaxation method, the Dirichlet-type method and active wave absorption. A sensitivity analysis has been conducted in order to quantify and compare the differences in terms of absorption quality between these methods. A reflection analysis based on an arbitrary number of wave gauges has been adopted to conduct the study. Tests include reflection analysis of linear, second- and fifth-order Stokes waves, solitary waves, cnoidal waves and irregular waves generated in an NWT. Wave breaking over a sloping bed and wave forces on a vertical cylinder are calculated, and the influence of the reflections on the wave breaking location and the wave forces on the cylinder is investigated. In addition, a comparison with another open-source CFD code, OpenFOAM, has been carried out based on published results. Some differences in the calculated quantities depending on the wave generation and absorption method have been observed. The active wave absorption method is seen to be more efficient for long waves, whereas the relaxation method performs better for shorter waves. The relaxation method-based numerical beach generally results in lower reflected waves in the wave tank for most of the cases simulated in this study. The comparably better performance of the relaxation method comes at the cost of larger computational requirements due to the relaxation zones that have to be included in the domain. The reflections in the NWT in REEF3D are generally lower than the published results for reflections using the active wave absorption method in the NWT based on OpenFOAM.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-06-14
      DOI: 10.3390/jmse6020073
      Issue No: Vol. 6, No. 2 (2018)
       
  • JMSE, Vol. 6, Pages 2: Automated Image Analysis of Offshore Infrastructure
           Marine Biofouling

    • Authors: Kate Gormley, Faron McLellan, Christopher McCabe, Claire Hinton, Joseph Ferris, David Kline, Beth Scott
      First page: 2
      Abstract: In the UK, some of the oldest oil and gas installations have been in the water for over 40 years and have considerable colonisation by marine organisms, which may lead to both industry challenges and/or potential biodiversity benefits (e.g., artificial reefs). The project objective was to test the use of an automated image analysis software (CoralNet) on images of marine biofouling from offshore platforms on the UK continental shelf, with the aim of (i) training the software to identify the main marine biofouling organisms on UK platforms; (ii) testing the software performance on 3 platforms under 3 different analysis criteria (methods A–C); (iii) calculating the percentage cover of marine biofouling organisms and (iv) providing recommendations to industry. Following software training with 857 images, and testing of three platforms, results showed that diversity of the three platforms ranged from low (in the central North Sea) to moderate (in the northern North Sea). The two central North Sea platforms were dominated by the plumose anemone Metridium dianthus; and the northern North Sea platform showed less obvious species domination. Three different analysis criteria were created, where the method of selection of points, number of points assessed and confidence level thresholds (CT) varied: (method A) random selection of 20 points with CT 80%, (method B) stratified random of 50 points with CT of 90% and (method C) a grid approach of 100 points with CT of 90%. Performed across the three platforms, the results showed that there were no significant differences across the majority of species and comparison pairs. No significant difference (across all species) was noted between confirmed annotations methods (A, B and C). It was considered that the software performed well for the classification of the main fouling species in the North Sea. Overall, the study showed that the use of automated image analysis software may enable a more efficient and consistent approach to marine biofouling analysis on offshore structures; enabling the collection of environmental data for decommissioning and other operational industries.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-03
      DOI: 10.3390/jmse6010002
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 3: Two Centuries of Climate Change and Climate
           Variability, East Coast Australia

    • Authors: Peter Helman, Rodger Tomlinson
      First page: 3
      Abstract: On the east Australian coast, climate change is expressed as a slowly rising sea level. Analysis of records, dating back over two centuries, also shows oscillating multidecadal ‘storm’ and ‘drought’ dominated climate periods that are distinct from long-term climate change. Climate variability, as expressed by these distinct multidecadal periods, is generally associated with phases of the Interdecadal Pacific Oscillation Index (IPO). Two centuries of climate and coastline response are examined for the central east coast of Australia, between Fraser Island and Coffs Harbour. The long record has been compiled by analysing a wide range of indicators and observations, including: historical accounts, storm records, sea level trends, assessment of storm erosion faces, and coastal movement in relation to fixed monuments, surveys, and maps. Periods of suppressed sea level, beach accretion, and drought were found to be associated with strongly positive IPO. Periods of higher sea level, increased storminess, and beach erosion were associated with strongly negative IPO. Understanding the behaviour of climate variability over different timescales has the potential to improve the understanding of, and responses to, climate change. This will be important in the sustainable management of geomorphic and ecological systems.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-03
      DOI: 10.3390/jmse6010003
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 4: Oil Spill Detection and Mapping Using Sentinel 2
           Imagery

    • Authors: Polychronis Kolokoussis, Vassilia Karathanassi
      First page: 4
      Abstract: Two object-based image analysis methods are developed for detecting oil spills from known natural outflows as well as light oil spill events using Sentinel 2 imagery. The methods are applied to Sentinel 2 images of a known area of natural oil outflow as well as on a Sentinel 2 image of a recent oil spill event along the south coast of Athens, Greece. The preliminary results are considered very successful and consistent, with a high degree of applicability to other Sentinel 2 satellite images. Further testing and fine tuning of the proposed object-based methodology should be carried out using atmospheric correction and ground truth.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-06
      DOI: 10.3390/jmse6010004
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 5: Quantifying Economic Value of Coastal Ecosystem
           Services: A Review

    • Authors: Seyedabdolhossein Mehvar, Tatiana Filatova, Ali Dastgheib, Erik de Ruyter van Steveninck, Roshanka Ranasinghe
      First page: 5
      Abstract: The complexity of quantifying ecosystem services in monetary terms has long been a challenging issue for economists and ecologists. Many case specific valuation studies have been carried out in various parts of the World. Yet, a coherent review on the valuation of coastal ecosystem services (CES), which systematically describes fundamental concepts, analyzes reported applications, and addresses the issue of climate change (CC) impacts on the monetary value of CES is still lacking. Here, we take a step towards addressing this knowledge gap by pursuing a coherent review that aims to provide policy makers and researchers in multidisciplinary teams with a summary of the state-of-the-art and a guideline on the process of economic valuation of CES and potential changes in these values due to CC impacts. The article highlights the main concepts of CES valuation studies and offers a systematic analysis of the best practices by analyzing two global scale and 30 selected local and regional case studies, in which different CES have been valued. Our analysis shows that coral reefs and mangroves are among the most frequently valued ecosystems, while sea-grass beds are the least considered ones. Currently, tourism and recreation services as well as storm protection are two of the most considered services representing higher estimated value than other CES. In terms of the valuation techniques used, avoided damage, replacement and substitute cost method as well as stated preference method are among the most commonly used valuation techniques. Following the above analysis, we propose a methodological framework that provides step-wise guidance and better insight into the linkages between climate change impacts and the monetary value of CES. This highlights two main types of CC impacts on CES: one being the climate regulation services of coastal ecosystems, and the other being the monetary value of services, which is subject to substantial uncertainty. Finally, a systematic four-step approach is proposed to effectively monetize potential CC driven variations in the value of CES.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-09
      DOI: 10.3390/jmse6010005
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 6: Antimacrofouling Efficacy of Innovative Inorganic
           Nanomaterials Loaded with Booster Biocides

    • Authors: Eldad Gutner-Hoch, Roberto Martins, Tania Oliveira, Frederico Maia, Amadeu Soares, Susana Loureiro, Chen Piller, Iris Preiss, Michal Weis, Severine Larroze, Tania Teixeira, João Tedim, Yehuda Benayahu
      First page: 6
      Abstract: The application of nano-structured compounds has been increasing rapidly in recent years, in several fields. The use of engineered nano-materials as carriers of antifouling compounds is just beginning and already reveals clear advantages compared to bulk active compounds, such as slowed and controlled release, novel functionality, and high loading capacity. This present study assesses the antifouling efficacy of two nanostructured materials, spherical mesoporous silica nanocapsules (SiNC) and Zn-Al layered double hydroxides (LDH), loaded with two commercial biocides, zinc prithione (ZnPT) and copper pyrithione (CuPT). The study used adult mussels from three geographical regions, the Atlantic Ocean, Mediterranean Sea, and the Red Sea, to examine the efficacy of the innovative compounds. The efficacy of these compounds on larvae of the bryozoan Bugula neritina from the Mediterranean Sea and the Red Sea was also examined. The results of this study demonstrated the environmentally friendly properties of unloaded LDH against the two-model systems, adult mussels or bryozoan larvae. ZnPT entrapped in LDH demonstrated the most effective antifouling compound against the two model systems. A comparison of the impact of the two compounds on macrofouling organisms from the different marine habitats examined in this study indicates a distinction associated with the organisms’ different ecosystems. The Red Sea mussels and bryozoans, representing a tropical marine ecosystem, yielded the highest efficacy values among tested Atlantic Ocean and Mediterranean Sea mussels and bryozoans.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-10
      DOI: 10.3390/jmse6010006
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 7: Oil Droplet Transport under Non-Breaking Waves: An
           Eulerian RANS Approach Combined with a Lagrangian Particle Dispersion
           Model

    • Authors: Roozbeh Golshan, Michel Boufadel, Victor Rodriguez, Xiaolong Geng, Feng Gao, Thomas King, Brian Robinson, Andrés Tejada-Martínez
      First page: 7
      Abstract: Oil droplet transport under a non-breaking deep water wave field is investigated herein using Computational Fluid dynamics (CFD). The Reynolds-averaged Navier–Stokes (RANS) equations were solved to simulate regular waves in the absence of wind stress, and the resulting water velocities agreed with Stokes theory for waves. The RANS velocity field was then used to predict the transport of buoyant particles representing oil droplets under the effect of non-locally generated turbulence. The RANS eddy viscosity exhibited an increase with depth until reaching a maximum at approximately a wave height below the mean water level. This was followed by a gradual decrease with depth. The impact of the turbulence was modeled using the local value of eddy diffusivity in a random walk framework with the added effects of the gradient of eddy diffusivity. The vertical gradient of eddy viscosity increased the residence time of droplets in the water column region of high diffusivity; neglecting the gradient of eddy diffusivity resulted in a deviation of the oil plume centroid by more than a half a wave height after 10 wave periods.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-15
      DOI: 10.3390/jmse6010007
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 8: Acknowledgement to Reviewers of Journal of Marine
           Science and Engineering in 2017

    • Authors: JMSE Editorial Office
      First page: 8
      Abstract: Peer review is an essential part in the publication process, ensuring that Journal of Marine Science and Engineering maintains high quality standards for its published papers.[...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-11
      DOI: 10.3390/jmse6010008
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 9: Integrated System Design for a Large Wind Turbine
           Supported on a Moored Semi-Submersible Platform

    • Authors: Jinsong Liu, Edwin Thomas, Lance Manuel, D. Griffith, Kelley Ruehl, Matthew Barone
      First page: 9
      Abstract: Over the past few decades, wind energy has emerged as an alternative to conventional power generation that is economical, environmentally friendly and, importantly, renewable. Specifically, offshore wind energy is being considered by a number of countries to harness the stronger and more consistent wind resource compared to that over land. To meet the projected “20% energy from wind by 2030” scenario that was announced in 2006, 54 GW of added wind energy capacity need to come from offshore according to a National Renewable Energy Laboratory (NREL) study. In this study, we discuss the development of a semi-submersible floating offshore platform with a catenary mooring system to support a very large 13.2-MW wind turbine with 100-m blades. An iterative design process is applied to baseline models with Froude scaling in order to achieve preliminary static stability. Structural dynamic analyses are performed to investigate the performance of the new model using a finite element method approach for the tower and a boundary integral equation (panel) method for the platform. The steady-state response of the system under uniform wind and regular waves is first studied to evaluate the performance of the integrated system. Response amplitude operators (RAOs) are computed in the time domain using white-noise wave excitation; this serves to highlight nonlinear, as well as dynamic characteristics of the system. Finally, selected design load cases (DLCs) and the stochastic dynamic response of the system are studied to assess the global performance for sea states defined by wind fields with turbulence and long-crested irregular waves.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-12
      DOI: 10.3390/jmse6010009
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 10: Evaluation of Underwater Image Enhancement
           Algorithms under Different Environmental Conditions

    • Authors: Marino Mangeruga, Marco Cozza, Fabio Bruno
      First page: 10
      Abstract: Underwater images usually suffer from poor visibility, lack of contrast and colour casting, mainly due to light absorption and scattering. In literature, there are many algorithms aimed to enhance the quality of underwater images through different approaches. Our purpose was to identify an algorithm that performs well in different environmental conditions. We have selected some algorithms from the state of the art and we have employed them to enhance a dataset of images produced in various underwater sites, representing different environmental and illumination conditions. These enhanced images have been evaluated through some quantitative metrics. By analysing the results of these metrics, we tried to understand which of the selected algorithms performed better than the others. Another purpose of our research was to establish if a quantitative metric was enough to judge the behaviour of an underwater image enhancement algorithm. We aim to demonstrate that, even if the metrics can provide an indicative estimation of image quality, they could lead to inconsistent or erroneous evaluations.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-16
      DOI: 10.3390/jmse6010010
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 11: How Well Do AR5 Sea Surface-Height Model
           Projections Match Observational Rates of Sea-Level Rise at the Regional
           Scale'

    • Authors: Phil Watson
      First page: 11
      Abstract: The reliance upon and importance of climate models continues to grow in line with strengthening evidence of a changing climate system and the necessity to provide credible projections for risk assessment to guide policy development, mitigation and adaptation responses. The utility of the models to project regional rates of sea-level rise over the course of the 21st century is reliant on evaluating model outputs against global observational data (principally altimetry products). This study compares rates of sea-level rise from observational data records (tide gauges) against the ensemble mean of the model-projection products used in AR5 at 19 sites around the world over the decade of common data coverage (2007–2016) using enhanced time-series analysis techniques. Although it could be concluded that the observational and model-projected average velocity agree (95% confidence level (CL)), error margins are comparatively wide, masking the fact that the mean velocity for the model-projection products exceed observational records for nearly all stations and Representative Concentration Pathway (RCP) experiments, and are likely in the range of 1.6–2.5 mm/year. The analysis might provide an early warning sign that the evaluation of ocean model components with respect to projected mean sea level could be relevantly improved.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-01
      DOI: 10.3390/jmse6010011
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 12: An Evaluation of the Large-Scale Implementation of
           Ocean Thermal Energy Conversion (OTEC) Using an Ocean General Circulation
           Model with Low-Complexity Atmospheric Feedback Effects

    • Authors: Yanli Jia, Gérard Nihous, Krishnakumar Rajagopalan
      First page: 12
      Abstract: Previous investigations of the large-scale deployment of Ocean Thermal Energy Conversions (OTEC) systems are extended by allowing some atmospheric feedback in an ocean general circulation model. A modified ocean-atmosphere thermal boundary condition is used where relaxation corresponds to atmospheric longwave radiation to space, and an additional term expresses horizontal atmospheric transport. This produces lower steady-state OTEC power maxima (8 to 10.2 TW instead of 14.1 TW for global OTEC scenarios, and 7.2 to 9.3 TW instead of 11.9 TW for OTEC implementation within 100 km of coastlines). When power production peaks, power intensity remains practically unchanged, at 0.2 TW per Sverdrup of OTEC deep cold seawater, suggesting a similar degradation of the OTEC thermal resource. Large-scale environmental effects include surface cooling in low latitudes and warming elsewhere, with a net heat intake within the water column. These changes develop rapidly from the propagation of Kelvin and Rossby waves, and ocean current advection. Two deep circulation cells are generated in the Atlantic and Indo-Pacific basins. The Atlantic Meridional Overturning Circulation (AMOC) is reinforced while an AMOC-like feature appears in the North Pacific, with deep convective winter events at high latitudes. Transport between the Indo-Pacific and the Southern Ocean is strengthened, with impacts on the Atlantic via the Antarctic Circumpolar Current (ACC).
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-01-22
      DOI: 10.3390/jmse6010012
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 13: Current Knowledge and Recent Advances in Marine
           Dinoflagellate Transcriptomic Research

    • Authors: Muhamad Akbar, Asmat Ahmad, Gires Usup, Hamidun Bunawan
      First page: 13
      Abstract: Dinoflagellates are essential components in marine ecosystems, and they possess two dissimilar flagella to facilitate movement. Dinoflagellates are major components of marine food webs and of extreme importance in balancing the ecosystem energy flux in oceans. They have been reported to be the primary cause of harmful algae bloom (HABs) events around the world, causing seafood poisoning and therefore having a direct impact on human health. Interestingly, dinoflagellates in the genus Symbiodinium are major components of coral reef foundations. Knowledge regarding their genes and genome organization is currently limited due to their large genome size and other genetic and cytological characteristics that hinder whole genome sequencing of dinoflagellates. Transcriptomic approaches and genetic analyses have been employed to unravel the physiological and metabolic characteristics of dinoflagellates and their complexity. In this review, we summarize the current knowledge and findings from transcriptomic studies to understand the cell growth, effects on environmental stress, toxin biosynthesis, dynamic of HABs, phylogeny and endosymbiosis of dinoflagellates. With the advancement of high throughput sequencing technologies and lower cost of sequencing, transcriptomic approaches will likely deepen our understanding in other aspects of dinoflagellates’ molecular biology such as gene functional analysis, systems biology and development of model organisms.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-01
      DOI: 10.3390/jmse6010013
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 14: Spatial Characteristics and Duration of Extreme
           Wave Events around the English Coastline

    • Authors: Thomas Dhoop, Travis Mason
      First page: 14
      Abstract: This paper presents an analysis of the spatial characteristics and duration of extreme wave events around the English coast. There are five geographic regions which are affected as coherent units under extreme wave conditions, incorporating a sixth micro-wave climate region (western Lyme Bay). Characteristic storm tracks are associated with each region. Storms affecting the East region (North Sea coast) seldom impact other areas of England, whilst in contrast, storms affecting the Southwest or Northwest also have some impact on the Southeast. Average storm duration varies from 5 h in the Northwest to 14 h on the East coast north of the Humber. Storm duration exceeding 12.5 h in the Southwest and East (northern half) near guarantees that storm waves will span High Water, when it is of most significance for beach management operations. Storms along the East coast can be associated with anticyclonic conditions, as well as low pressure systems.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-02
      DOI: 10.3390/jmse6010014
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 15: A Marine Information System for Environmental
           Monitoring: ARGO-MIS

    • Authors: Gabriele Pieri, Michele Cocco, Ovidio Salvetti
      First page: 15
      Abstract: Sea shipping routes have become very crowded and this, coupled with an always increasing demand of oil based products, contributes to the increase in maritime traffic density, as a consequence pollution risks have increased. Therefore, it is important to have information systems capable of detecting and monitoring environmental endangering situations like oil spills at sea. In this paper, a Marine Information System, acting as an integrated and inter-operable monitoring tool is proposed and discussed. The discussion focuses on a system that is able to integrate different data acquired from various electronic sensors, and that is inter-operable among marine operators and ship traffic authorities. The available data on the system are all geo-referenced, and flows seamlessly through the system, where they are integrated in a consistent and usable manner. An important result of this integration is the capability to produce a collection of proactive services such as Decision Support ones, which can be used to improve the functionalities and facilities concerned in an intervention operation. Through the implementation of these services, we aim to demonstrate how an efficient environmental management system could benefit from being supported by a Marine Information System that can provide the dynamic links between different data, models and actors.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-05
      DOI: 10.3390/jmse6010015
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 16: Numerical Investigation of Extreme Wave-Induced
           Loading on Box Girder in Marine Environment

    • Authors: Baoshan Xiang, Zhiying Yang, Bing Zhu, Ruitao Yin
      First page: 16
      Abstract: In this paper, a 2D numerical model for wave-girder interaction was proposed to estimate the maximum wave forces on the box girder of a coastal bridge under extreme wave conditions. The Reynolds Averaged Navier-Stokes (RANS) equations were applied to simulate water wave motion and the Volume of Fluid (VOF) method was used to track the free surface. In this study, the developed 2D numerical model was validated by first comparing with experimental data. Then, a set of parametric studies was conducted to examine the effects of the wave heights, wave periods, water depths and submerged coefficients on the wave force on the box girder under extreme wave conditions. Finally, a function to predict the extreme wave-induced forces on the box girder under various wave conditions was proposed for engineering practice.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-11
      DOI: 10.3390/jmse6010016
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 17: The Level of Automation in Emergency Quick
           Disconnect Decision Making

    • Authors: Imset Marius, Falk Kristin, Kjørstad Marianne, Nazir Salman
      First page: 17
      Abstract: As a key measure for safety and environmental protection during offshore well operations, drill rigs are equipped with Emergency Quick Disconnect (EQD) systems. However, an EQD operation is in itself considered a risky operation with a major economic impact. For this reason, it is of great importance to aid the operators in their assessment of the situation at all times, and help them make the best decisions. However, despite the availability of such systems, accidents do happen. This demonstrates the vulnerability of our human decision-making capabilities in extremely stressful situations. One way of improving the overall human-system performance with respect to EQD is to increase the level and quality of the automation and decision support systems. Although there is plenty of evidence that automated systems have weaknesses, there is also evidence that advanced software systems outperform humans in complex decision-making. The major challenge is to make sure that EQD is performed when necessary, but there is also a need to decrease the number of false EQDs. This paper applies an existing framework for levels of automation in order to explore the critical decision process leading to an EQD. We provide an overview of the benefits and drawbacks of existing automation and decision support systems vs. manual human decision-making. Data are collected from interviews of offshore users, suppliers, and oil companies, as well as from formal operational procedures. Findings are discussed using an established framework for the level of automation. Our conclusion is that there is an appropriate level of automation in critical situations related to the loss of the position of the drill rig, and that there is the promising potential to increase the autonomy level in a mid- and long-term situation assessment.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-12
      DOI: 10.3390/jmse6010017
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 18: Construction of a Static Model for Power
           Generation of OTEC Plant Using Uehara Cycle Based on Experimental Data

    • Authors: Yoshitaka Matsuda, Takuma Yoshitake, Takenao Sugi, Satoru Goto, Takafumi Morisaki, Takeshi Yasunaga, Yasuyuki Ikegami
      First page: 18
      Abstract: This paper considers the construction of a static model for the power generation of an ocean thermal energy conversion (OTEC) plant using Uehara cycle. The model is constructed based on experimental data obtained from an actual experimental OTEC plant. In this paper, two kinds of static models are proposed. In both models, the relations among significant quantities are represented by polynomials. The polynomials are determined via least squares for experimental data, and the orders of polynomial which minimize the integral of absolute error between experimental data and simulation results of power generation are adopted. The usefulness and limitations of the proposed models are evaluated by simulation results.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-15
      DOI: 10.3390/jmse6010018
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 19: Coastal Sea Levels, Impacts, and Adaptation

    • Authors: Thomas Wahl, Sally Brown, Ivan D. Haigh, Jan Even Øie Nilsen
      First page: 19
      Abstract: Sea-level rise (SLR) poses a great threat to approximately 10% of the world’s population residing in low-elevation coastal zones (i.e., land located up to 10 m of present-day mean sea-level (MSL))[...]
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-21
      DOI: 10.3390/jmse6010019
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 20: Determination of the Potential Thermal Gradient
           for the Mexican Pacific Ocean

    • Authors: Alejandro García Huante, Yandy Rodríguez Cueto, Rodolfo Silva, Edgar Mendoza, Luis A. Vega
      First page: 20
      Abstract: The energy potential of the oceanic thermal gradients of the Mexican Pacific Ocean was valued theoretically, using seasonal oceanographic data on surface and 1000 m depth ocean temperatures from 1955 to 2013, taken from the World Ocean Database (WOD). The study was carried out to determine possible sites for Ocean Thermal Energy Conversion (OTEC), assuming that the minimum usable gradient is 20 °C and the maximum profitable distance from the extraction site to the shore is 10 km. Geographic Information System tools were used to compute thermal gradients and distances to shore all along the Mexican coast. Then, the optimal sites were identified. The results show that the best sites for OTEC exploitation are found in the southern Pacific coast on the littoral of the states of Guerrero and Oaxaca.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-02-21
      DOI: 10.3390/jmse6010020
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 21: Ocean Thermal Energy Conversion Using Double-Stage
           Rankine Cycle

    • Authors: Yasuyuki Ikegami, Takeshi Yasunaga, Takafumi Morisaki
      First page: 21
      Abstract: Ocean Thermal Energy Conversion (OTEC) using non-azeotropic mixtures such as ammonia/water as working fluid and the multistage cycle has been investigated in order to improve the thermal efficiency of the cycle because of small ocean temperature differences. The performance and effectiveness of the multistage cycle are barely understood. In addition, previous evaluation methods of heat exchange process cannot clearly indicate the influence of the thermophysical characteristics of the working fluid on the power output. Consequently, this study investigated the influence of reduction of the irreversible losses in the heat exchange process on the system performance in double-stage Rankine cycle using pure working fluid. Single Rankine, double-stage Rankine and Kalina cycles were analyzed to ascertain the system characteristics. The simple evaluation method of the temperature difference between the working fluid and the seawater is applied to this analysis. From the results of the parametric performance analysis it can be considered that double-stage Rankine cycle using pure working fluid can reduce the irreversible losses in the heat exchange process as with the Kalina cycle using an ammonia/water mixture. Considering the maximum power efficiency obtained in the study, double-stage Rankine and Kalina cycles can improve the power output by reducing the irreversible losses in the cycle.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-01
      DOI: 10.3390/jmse6010021
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 22: Macro and Micro Properties of Organic Matter in
           Hydraulic Mud Consolidation

    • Authors: Jing Song, Yu-Shuang Yang, Zhi-Qing Liu, Xue Li
      First page: 22
      Abstract: Due to the co-existence of multiple organics and multiple length scales of the structure, quantitative characterization of the microstructure of organic matter in hydraulic mud consolidations, and understanding the impact on its mechanical properties have been challenging topics. This article attempts to tackle the challenge using lab experiments and a data-constrained modelling (DCM) approach combined with multi-energy synchrotron-based X-ray micro-CT (computed tomography). In this paper, scanning electron microscopy (SEM) and other different technical means were combined to study the microstructure of hydraulic mud composition and distribution. One unmodified hydraulic mud and four remolded samples were analyzed in vacuum preloading tests corresponding to organic matter contents of 1.65%, 3.75%, 5.15%, 8.65%, and 11.15%, respectively. Organic matter plays a significant role in hindering the shear strength of consolidation. Macro- and microstructure under different pressures could be extracted by the DCM and X-ray CT. The DCM-reconstructed microstructure of fine-grained soil from hydraulic mud is presented by four groups: organic matter, two groups of minerals, and pores. Different groups are displayed with different colors, which could clarify the distributions and density degrees of each component (group). The macro- and microstructures and the distribution of organic matter were quantified and compared among groups. It was demonstrated that the mechanical properties of the organic matter were closely correlated to the meso- and nano-scale clusters of porosity and minerals. The variation of organic clusters with loading pressure, and the number of sub-macro organic clusters, were small. Three scales of organic cluster (40–400 μm, 4–40 μm, and 0.4–4 μm) changed visibly in consolidation at 200 kPa and 800 kPa. The analysis has shown that pressures of 100 kPa and 400 kPa could be used as two characteristic values of structure change of hydraulic mud, which perhaps matched the turning points of destruction. The DCM approach, combined with multi-energy synchrotron-based X-ray micro-CT presented here, are applicable in studying the relationship between the microstructure and macro-properties for various other engineering materials.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-01
      DOI: 10.3390/jmse6010022
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 23: Quantitative Analysis of 3D Reconstruction
           Parameters of Multi-Materialsin Soft Clay

    • Authors: Zhiqing Liu, Jing Song, Yushuang Yang, Xue Li
      First page: 23
      Abstract: The results of the three-dimensional reconstruction of soil were derived from the X-ray absorption coefficient of the material itself. However, the absorption coefficient is not a fixed value, and is related to densities, chemical molecular weight, and the weight percentages of chemical components. How to accurately obtain the density of one component is a vital issue in multi-materials. In this study, the influence of the physical parameters of each component in the data-constrained modeling (DCM) of the microstructure of soft clay was investigated. The results showed that density changes were more prominent. A reasonable multi-component density was calculated, and the density of organic matter had a significant effect on the volume percentage of three-dimensional soft clay. In the clay mineral montmorillonite, the density significantly affected the volume percentage data, which directly limited the accuracy of the material distribution analysis. Based on this, other physical parameters of each component in the data constraint model could be further explored. Based on the density value of the simple material, a reasonable multi-materials density was calculated, which provides a quantitative method for the evolution analysis of soil structure.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-05
      DOI: 10.3390/jmse6010023
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 24: Monitoring Litter Inputs from the Adour River
           (Southwest France) to the Marine Environment

    • Authors: Antoine Bruge, Cristina Barreau, Jérémy Carlot, Hélène Collin, Clément Moreno, Philippe Maison
      First page: 24
      Abstract: Rivers are major pathways for litter to enter the ocean, especially plastic debris. Yet, further research is needed to improve knowledge on rivers contribution, increase data availability, refine litter origins, and develop relevant solutions to limit riverine litter inputs. This study presents the results of three years of aquatic litter monitoring on the Adour river catchment (southwest of France). Litter monitoring consisted of collecting all litter stranded on river banks or stuck in the riparian vegetation in defined areas identified from cartographic and hydromorphological analyses, and with the support of local stakeholders. Litter samples were then sorted and counted according to a list of items containing 130 categories. Since 2014, 278 litter samplings were carried out, and 120,632 litter items were collected, sorted, and counted. 41% of litter could not be identified due to high degradation. Food and beverage packaging, smoking-related items, sewage related debris, fishery and mariculture gear, and common household items represented around 70% of identifiable items. Overall, the present study contributes to our knowledge of litter sources and pathways, with the target of reducing the amounts entering the ocean. The long-term application of this monitoring is a way forward to measure societal changes as well as assess effectiveness of measures.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-06
      DOI: 10.3390/jmse6010024
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 25: A Preliminary Investigation of the Effect of Ocean
           Thermal Energy Conversion (OTEC) Effluent Discharge Options on Global OTEC
           Resources

    • Authors: Gérard Nihous
      First page: 25
      Abstract: A simple algorithm previously used to evaluate steady-state global Ocean Thermal Energy Conversion (OTEC) resources is extended to probe the effect of various effluent discharge methodologies. It is found that separate evaporator and condenser discharges potentially increase OTEC net power limits by about 60% over a comparable mixed discharge scenario. This stems from a relatively less severe degradation of the thermal resource at given OTEC seawater flow rates, which corresponds to a smaller heat input into the ocean. Next, the most practical case of a mixed discharge into the mixed layer is found to correspond to only 80% of the so-called baseline case (mixed discharge at a water depth of initial neutral buoyancy). In general, locating effluent discharges at initial neutral-buoyancy depths appears to be nearly optimal in terms of OTEC net power production limits. The depth selected for the OTEC condenser effluent discharge, however, has by far the greatest impact. Clearly, these results are preliminary and should be investigated in more complex ocean general circulation models.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-12
      DOI: 10.3390/jmse6010025
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 26: Small-Scale Renewable Energy Converters for
           Battery Charging

    • Authors: Mohd Ayob, Valeria Castellucci, Malin Göteman, Joakim Widén, Johan Abrahamsson, Jens Engström, Rafael Waters
      First page: 26
      Abstract: This paper presents two wave energy concepts for small-scale electricity generation. In the presented case, these concepts are installed on the buoy of a heaving, point-absorbing wave energy converter (WEC) for large scale electricity production. In the studied WEC, developed by Uppsala University, small-scale electricity generation in the buoy is needed to power a tidal compensating system designed to increase the performance of the WEC in areas with high tides. The two considered and modeled concepts are an oscillating water column (OWC) and a heaving point absorber. The results indicate that the OWC is too small for the task and does not produce enough energy. On the other hand, the results show that a hybrid system composed of a small heaving point absorber combined with a solar energy system would be able to provide a requested minimum power of around 37.7 W on average year around. The WEC and solar panel complement each other, as the WEC produces enough energy by itself during wintertime (but not in the summer), while the solar panel produces enough energy in the summer (but not in the winter).
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-13
      DOI: 10.3390/jmse6010026
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 27: Prediction of the Open-Water Performance of Ducted
           Propellers with a Panel Method

    • Authors: João Baltazar, Douwe Rijpkema, José Falcão de Campos, Johan Bosschers
      First page: 27
      Abstract: In the present work, a comparison between the results obtained by a panel code with a Reynolds-averaged Navier-Stokes (RANS) code is made to obtain a better insight on the viscous effects of the ducted propeller and on the limitations of the inviscid flow model, especially near bollard pull conditions or low advance ratios, which are important in the design stage. The analysis is carried out for propeller Ka4-70 operating inside duct 19A. From the comparison, several modelling aspects are studied for improvement of the inviscid (potential) flow solution. Finally, the experimental open-water data is compared with the panel method and RANS solutions. A strong influence of the blade wake pitch, especially near the blade tip, on the ducted propeller force predictions is seen. A reduction of the pitch of the gap strip is proposed for improvement of the performance prediction at low advance ratios.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-19
      DOI: 10.3390/jmse6010027
      Issue No: Vol. 6, No. 1 (2018)
       
  • JMSE, Vol. 6, Pages 28: Seasonal Variability of Wind Sea and Swell Waves
           Climate along the Canary Current: The Local Wind Effect

    • Authors: Alvaro Semedo
      First page: 28
      Abstract: A climatology of wind sea and swell waves along the Canary eastern boundary current area, from west Iberia to Mauritania, is presented. The study is based on the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis ERA-Interim. The wind regime along the Canary Current, along west Iberia and north-west Africa, varies significantly from winter to summer. High summer wind speeds generate high wind sea waves, particularly along the coasts of Morocco and Western Sahara. Lower winter wind speeds, along with stronger extratropical storms crossing the North Atlantic sub-basin up north lead to a predominance of swell waves in the area during from December to February. In summer, the coast parallel wind interacts with the coastal headlands, increasing the wind speed and the locally generated waves. The spatial patterns of the wind sea or swell regional wave fields are shown to be different from the open ocean, due to coastal geometry, fetch dimensions, and island sheltering.
      Citation: Journal of Marine Science and Engineering
      PubDate: 2018-03-20
      DOI: 10.3390/jmse6010028
      Issue No: Vol. 6, No. 1 (2018)
       
 
 
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