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Journal of Marine Science and Application
Journal Prestige (SJR): 0.288  Citation Impact (citeScore): 1 Number of Followers: 3  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1993-5048 - ISSN (Online) 1671-9433 Published by Springer-Verlag  [2468 journals]
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- Maritime Energy Transition: Future Fuels and Future Emissions
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Abstract: Abstract The lifecycle greenhouse gas (GHG) emissions (Well-to-Wake) from maritime transport must be reduced by at least 50% in absolute values by 2050 to contribute to the ambitions of the Paris Agreement (2015). A transition from conventional fuels to alternative fuels with zero or lower GHG emissions is viewed as the most promising avenue to reach the GHG reductions. Whereas GHG and toxic pollutants emitted from the use of fossil fuels (heavy fuel oil (HFO) and marine gas/diesel oil (MGO/MDO)) are generally well understood, the emissions associated with the new fuel options are only now being measured and communicated. This review provides an outlook on fuels that could help shipping respond to the decarbonization effort including Liquefied Petroleum Gas (LPG), Liquefied Natural Gas (LNG), methanol, ammonia, and hydrogen. A quantification of the pollutants associated from the use of these fuels is provided and challenges and barriers to their uptake are discussed.
PubDate: 2023-09-07
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- Techno-Economic Comparison of Dual-fuel Marine Engine Waste Energy
Recovery Systems-
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Abstract: Abstract Nowadays alternative and innovative energy recovery solutions are adopted on board ships to reduce fuel consumption and harmful emissions. According to this, the present work compares the engine exhaust gas waste heat recovery and hybrid turbocharger technologies, which are used to improve the efficiency of a dual-fuel four-stroke (DF) marine engine. Both solutions aim to satisfy partly or entirely the ship’s electrical and/or thermal loads. For the engine exhaust gas waste heat recovery, two steam plant schemes are considered: the single steam pressure and the variable layout (single or dual steam pressure plant). In both cases, a heat recovery steam generator is used for the electric power energy generation through a steam turbine. The hybrid turbocharger is used to provide a part of the ship’s electric loads as well. The thermodynamic mathematical models of DF engines, integrated with the energy recovery systems, are developed in a Matlab-Simulink environment, allowing the comparison in terms of performance at different engine loads and fuels, which are Natural Gas (NG) and High Fuel Oil (HFO). The use of NG always involves better efficiency of the system for all the engine working conditions. It results that the highest efficiency value achievable is 56% at 50% maximum continuous rating (MCR) engine load.
PubDate: 2023-09-07
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- Decarbonization of Maritime Transportation: A Case Study for Turkish Ship
Fleet-
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Abstract: Abstract Climate change and global warming are among the most severe threats to the global ecosystem, caused by greenhouse gas emissions. Therefore, all industries that cause environmental emissions should collaborate in the struggle against climate change. In this context, the International Maritime Organization (IMO) approved the initial greenhouse gas strategy at the MEPC 72 session in April 2018 to achieve targets for 2050. With this strategy, the IMO aims to create and improve new regulations that can enhance energy efficiency to achieve their short-term, midterm, and long-term goals. In this study, one of the novel terms, energy efficiency existing ship index (EEXI) values, has been calculated for the Turkish fleet to guide the maritime sector. The Turkish fleet in the study refers to the Turkish-owned vessels both sailing with a national or international flag. In accordance with this regulation, the number of Turkish fleets that were identified as either above or below the IMO reference lines has been determined. Additionally, EEXI values have been recalculated using the engine power limitation (EPL) method for ships that exceed the required limits, and the success rate of this method has been estimated. As a result, the application of EPL increased the number of ships below the Phase 2 reference line from 15.6 % to 53.1 %. To the best of our knowledge, this research, which has been carried out on all Turkish-owned ships, is the first study intended to serve as a guide for other ship owners in the global maritime industry regarding energy efficiency management.
PubDate: 2023-09-07
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- Numerical Investigation on Different Configurations of Offshore Fish Cages
in Submerged Conditions Subjected to Regular Waves-
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Abstract: Abstract The present research work concerns about the hydrodynamic behaviors of the open net offshore fish cages of single, double and 4-cage systems subjected to regular sinusoidal waves. The open net semisubmersible rigid cage is square in shape and analyzed numerically using ANSYS AQWA software. Frequency and time domain analyses are carried out for each case. The hydrodynamic parameters such as added mass, radiation potential damping, motion responses and mooring line tensions are considered as performance indicators to conclude as the best arrangements among three different cages. The single cage and windward side of all cages exhibit identical performance in all hydrodynamic parameters. The leeward side of each cage shows lesser parametric values than the windward side cages. Based on the performance indicators, it is concluded that the grid system containing four cage arrangements provides better performance than three other cage configurations. An experimental model of 1: 75 scale is fabricated and wave flume studies are conducted to validate the present numerical model. The cage is placed at a water depth of 55 cm and subjected to wave heights of 12 cm and 14 cm with wave periods ranging from 0.8 s to 2.2 s with an interval of 0.2 s are considered. The same wave flume boundary conditions are adopted for numerical simulations and results are in good agreement with experimental work results.
PubDate: 2023-09-01
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- Approach for Scheduling Automatic Guided Vehicles Considering Equipment
Failure and Power Management-
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Abstract: Abstract Intermediate charging and sudden failure of automatic guided vehicles (AGVs) interrupt and severely affect the stability and efficiency of scheduling. Therefore, an AGV scheduling approach considering equipment failure and power management is proposed for outfitting warehouses. First, a power consumption model is established for AGVs performing transportation tasks. The powers for departure and task consumption are used to calculate the AGV charging and return times. Second, an optimization model for AGV scheduling is established to minimize the total transportation time. Different conditions are defined for the overhaul and minor repair of AGVs, and a scheduling strategy for responding to sudden failure is proposed. Finally, an algorithm is developed to solve the optimization model for a case study. The method can be used to plan the charging time and perform rescheduling under sudden failure to improve the robustness and dynamic response capability of AGVs.
PubDate: 2023-09-01
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- Comparative Study of Numerical Methods for Predicting Wave-Induced Motions
and Loads on a Semisubmersible-
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Abstract: Abstract Numerical simulation tools based on potential-flow theory and/or Morison’s equation are widely used for predicting the hydrodynamic responses of floating offshore wind platforms. In general, these simplified approaches are used for the analysis under operational conditions, albeit with a carefully selected approach to account for viscous effects. Nevertheless, due to the limit hydrodynamic modelling to linear and weakly nonlinear models, these approaches severely underpredict the low-frequency nonlinear wave loads and dynamic responses of a semisubmersible. They may not capture important nonlinearities in severe sea states. For the prediction of wave-induced motions and loads on a semisubmersible, this work systematically compares a fully nonlinear viscous-flow solver and a hybrid model combining the potential-flow theory with Morison-drag loads in steep waves. Results show that when nonlinear phenomena are not dominant, the results obtained by the hybrid model and the high-fidelity method show reasonable agreement, while larger discrepancies occur for highly nonlinear regular waves. Specifically, regular waves with various steepness over different frequencies are focused in the present study, which supplements the understanding in applicability of these two groups of method.
PubDate: 2023-09-01
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- Structural Optimization and Stability Analysis for Supercavitating
Projectiles-
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Abstract: Abstract Stability is the key issue for kinetic-energy supercavitating projectiles. Our previous work established a six degrees of freedom (DOF) dynamic model for supercavitating projectiles. However, the projectile’s structure did not meet our current design specifications (its sailing distance could reach 100 m at an initial speed of 500 m/s). The emphasis of this study lies in optimizing the projectile’s configuration. Therefore, a program was developed to optimize the projectile’s structure to achieve an optimal design or the largest sailing distance. The program is a working optimal method based on the genetic algorithm (GA). Additionally, the convergence standard and population producing strategy were improved, which greatly elevated the calculation speed and precision. To meet design specifications, the improved GA was combined with the 6DOF model, which establishes a dynamic optimization problem. The new projectile’s structure was obtained by solving this problem. Then, the new structures’ dynamic features were compared with the ideals proposed in this paper. The criterion of stability, which is called weakened self-stability, was redefined based on the results. The weakened self-stability is the optimal stability for an actual kinetic projectile motion, and it is instructive for the design of supercavitating projectiles in the future.
PubDate: 2023-09-01
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- Fractional Super-Twisting/Terminal Sliding Mode Protocol for Nonlinear
Dynamical Model: Applications on Hovercraft/Chaotic Systems-
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Abstract: Abstract Fractional terminal and super-twisting as two types of fractional sliding mode controller are addressed in the present paper. The proposed methodologies are planned for both the nonlinear fractional-order chaotic systems and the nonlinear factional model of Hovercraft. The suggested procedure guarantees the asymptotic stability of fractional-order chaotic systems based on Lyapunov stability theorem, by presenting a set of fractional-order laws. Compared to the previous studies that concentrate on sliding mode controllers with unwanted chattering phenomena, the proposed methodologies deal with chattering reduction of terminal sliding mode controller/super twisting to converge to desired value in finite time, consequently. The main advantages of the offered controllers are 1) closed-loop system stability, 2) robustness against external disturbances and uncertainties, 3) finite time zero-convergence of the output tracking error, and 4) chattering phenomena reduction. Finally, the simulation results show the performance of the approaches both on the chaotic and Hovercraft models.
PubDate: 2023-09-01
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- Deep Learning in Maritime Autonomous Surface Ships: Current Development
and Challenges-
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Abstract: Abstract Autonomous surface ships have become increasingly interesting for commercial maritime sectors. Before deep learning (DL) was proposed, surface ship autonomy was mostly model-based. The development of artificial intelligence (AI) has prompted new challenges in the maritime industry. A detailed literature study and examination of DL applications in autonomous surface ships are still missing. Thus, this article reviews the current progress and applications of DL in the field of ship autonomy. The history of different DL methods and their application in autonomous surface ships is briefly outlined. Then, the previously published works studying DL methods in ship autonomy have been categorized into four groups, i.e., control systems, ship navigation, monitoring system, and transportation and logistics. The state-of-the-art of this review paper majorly lies in presenting the existing limitations and innovations of different applications. Subsequently, the current issues and challenges for DL application in autonomous surface ships are discussed. In addition, we have proposed a comparative study of traditional and DL algorithms in ship autonomy and also provided the future research scope as well.
PubDate: 2023-09-01
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- Research on the Hydrodynamic and Cavitation Performance of Semi-Balanced
Twisted Rudders-
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Abstract: Abstract In this study, we designed a new, semi-balanced, twisted rudder to reduce the surface cavitation problem of medium-high-speed surface warships. Based on the detached eddy simulation (DES) with the Spalart-Allmaras (SA) model (SA-DES) and the volume of fluid (VOF) method, the hydrodynamic and cavitation performances of an ordinary semi-balanced rudder and semi-balanced twisted rudder at different rudder angles were numerically calculated and compared using the commercial computational fluid dynamics (CFD) software STAR-CCM+ with the whole-domain structured grid. The calculation results showed that, under the same working conditions, the maneuverability of the semi-balanced twisted rudder basically remained unchanged compared with that of the ordinary semi-balanced rudder. Furthermore, the surface cavitation range of the semi-balanced twisted rudder was much smaller, and the inception rudder angle of the rudder surface cavitation increased by at least 5° at the maximum speed. In conclusion, the semi-balanced twisted rudder effectively reduced the cavitation of the rudder surface without reducing the rudder effect and exhibited excellent anti-cavitation performance.
PubDate: 2023-09-01
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- Application of CRITIC–EDAS-Based Approach in Structural Health
Monitoring and Maintenance of Offshore Wind Turbine Systems-
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Abstract: Abstract Performing structural health monitoring (SHM) and maintaining an offshore wind turbine system (OWTS) involve periodic observations, analysis, and repairs of the malfunctioning part(s) of the system. In this study, criteria importance through inter criteria correlation–evaluation based on distance from average solution methodology is employed to analyze SHM and maintenance technologies for OWTS. Their various applications are highlighted, and the technologies are prioritized using six indicators, namely, compatibility, potential cost reduction, needed investment, technology maturity, ease of application and potential reliability, and availability and maintainability of the considered technology. The study also aimed to improve the reliability of OWTS and minimize its maintenance cost. The results indicate that the technology’s ease of application, with a weight of 0.201 8, is the most important criterion. Furthermore, mathematical models as an SHM, along with maintenance technology, is ranked as the best alternative with an appraisal score of 0.770 6 and is considered more advantageous than other alternatives. This study provides a new research direction toward improving OWTS reliability. The findings will also aid the decision making of practitioners and researchers in the field of marine and offshore industry in relation to the optimal operations of OWTS.
PubDate: 2023-09-01
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- Time-Varying Channel Estimation and Symbol Detection for Underwater
Acoustic FBMC-OQAM Communications-
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Abstract: Abstract Filter bank multicarrier (FBMC) systems with offset quadrature amplitude modulation (OQAM) need long data blocks to achieve high spectral efficiency. However, the transmission of long data blocks in underwater acoustic (UWA) communication systems often encounters the challenge of time-varying channels. This paper proposes a time-varying channel tracking method for short-range high-rate UWA FBMC-OQAM communication applications. First, a known preamble is used to initialize the channel estimation at the initial time of the signal block. Next, the estimated channel is applied to detect data symbols at several symbol periods. The detected data symbols are then reused as new pilots to estimate the next time channel. In the above steps, the unified transmission matrix model is extended to describe the time-varying channel input–output model in this paper and is used for symbol detection. Simulation results show that the channel tracking error can be reduced to less than −20 dB when the channel temporal coherence coefficient exceeds 0.75 within one block period of FBMC-OQAM signals. Compared with conventional known-pilot-based methods, the proposed method needs lower system overhead while exhibiting similar time-varying channel tracking performance. The sea trial results further proved the practicability of the proposed method.
PubDate: 2023-09-01
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- Wave Energy Damping due to Coupled Porous Structure and Submerged Porous
Plate-
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Abstract: Abstract The present study investigates the wave-damping characteristics due to the combination of bottom-standing porous structure, submerged porous plate, and fully-extended porous structure of finite width using the small amplitude wave theory. The hydrodynamic characteristics such as reflection, transmission, and dissipation coefficients are determined to analyse the wave energy dissipation by the composite breakwater using the matched eigenfunction expansion method and orthogonal mode-coupling relation. Darcy’s law is incorporated to the flow through porous media. The composite breakwater system is investigated experimentally to validate and compare the numerical results with the physical model study. The complex porous effect parameter for the submerged plate is incorporated in the numerical analysis, which represents the reactance and resistance of the porous structure. The wave forces on the submerged plate and porous structure for the composite breakwater are investigated by considering the effects of changing parameters such as structural porosity, plate submergence, angle of incidence, width of the submerged porous structure and distance between the structures. The study illustrates that the increasing width of the fully-extended porous structure improves the performance of the breakwater system. The proposed study on the composite breakwater yields an useful information for wave energy attenuation, which can be designed and implemented in coastal and harbour areas to achieve wave tranquillity.
PubDate: 2023-09-01
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- Optimisation of a Multi-Body Three Floats Wave Energy Converter in
Irregular Waves-
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Abstract: Abstract A multi-body wave energy converter, consisting of three floats and modeled as a two body problem, is optimised to enhance its mean absorbed power using the Response Surface Optimisation Method. The optimisation focuses on two input parameters namely; the floats’ diameters and the spacing, in various sea states and at different PTO dampings. A frequency domain analysis is performed for the WEC model scaled at 1:50 in regular and irregular waves. Obtained results are validated against numerical and experimental data available in the literature. Validations show good agreement against the unmoored model’s added mass, radiation damping, response amplitude operator, mean absorbed power and, capture width ratio. The sea states selected for optimisation are represented by a JONSWAP wave spectrum with, a range of significant wave heights (0.04 to 0.06 m) and a range of peak periods (0.8 to 1.3 s). This corresponds to (2 to 3 m) significant wave heights and (5.6 to 9.2 s) peak periods in full scale. Results show that the optimised WEC model demonstrates good and consistent enhancement of its mean absorbed power and capture width ratio.
PubDate: 2023-09-01
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- Analytical and Numerical Study of Piston-Type Active Wave Absorbers with
Different Draft Ratios-
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Abstract: Abstract For active wave absorbers in force-control mode, the optimal feedback (control) force provided by the control system depends on the hydrodynamic forces. This work investigates a piston-type wave absorber with different draft-to-water depth ratios, focusing on the frequency-dependent hydrodynamic coefficients, wave absorption efficiency, wave absorber displacement and velocity, and control force. Analytical results were derived based on potential flow theory, confirming that regular incident waves can be fully absorbed by the piston-type active wave absorber at any draft ratio by optimizing the control force. The results for the wave tank with a typical water depth of 3 m were studied in detail. The draft ratio has a strong influence on the hydrodynamic coefficients. At the maximum wave absorption efficiency, the displacement and velocity amplitudes are sensitive to the draft ratio in the low-frequency region, increase with decreasing draft ratio, and are independent of the mass of the wave absorber. The control force required can be extremely large for a draft ratio greater than 1/3. The control force increases significantly as the draft ratio increases. The mass of the wave absorber has a weak influence on the control force. A time-domain numerical method based on the boundary element method was developed to verify the analytical solutions. Perfect agreements between the analytical solutions and the numerical results were obtained.
PubDate: 2023-09-01
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- Development of a New Concept of Multimission Pollution Control Vessel and
Optimization of its Bulbous Bow-
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Abstract: Abstract Controlling marine pollution caused by hydrocarbons spilling from oil tanker accidents and oil rigs is urgently needed. Conventional pollution control vessels currently in service worldwide do not meet certain safety criteria, storage capacities, and response times owing to their technical shortcomings. This study proposes a new concept of multimission and autonomous antipollution vessels capable of acting quickly and efficiently to counter such pollution threats. The objective of this study is to carry out a total and rapid recovery of the spilled oil slick in complete safety. Hence, optimizing the bulbous bow adapted to the pollution control vessel during its displacement is necessary to horizontally straighten the accompanying waves formed around the hull and to laminate the flow upstream of the side openings for the recovery of spilled oil. This optimization improves the nautical qualities specific to this ship to reduce the total resistance to progress and to standardize the flow upstream of the side openings to allow the collection of spilled oil at high speed. This optimization study can open a field of application for the construction of modern multi-mission pollution control vessels. Tests in hull basins will be planned to validate and adjust the results obtained from the simulations.
PubDate: 2023-09-01
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- Autopilot Design for an Unmanned Surface Vehicle Based on Backstepping
Integral Technique with Experimental Results-
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Abstract: Abstract Controller tuning is the correct setting of controller parameters to control complex dynamic systems appropriately and with high accuracy. Therefore, this study addressed the development of a method for tuning the heading controller of an unmanned surface vehicle (USV) based on the backstepping integral technique to enhance the vehicle behavior while tracking a desired position for water monitoring missions. The vehicle self-steering system (autopilot system) is designed theoretically and tested via a simulation. Based on the Lyapunov theory, the stability in the closed-loop system is guaranteed, and the convergence of the heading tracking errors is obtained. In addition, the designed control law is implemented via a microcontroller and tested experimentally in real time. Conclusion, experimental results were carried out to verify the robustness of the designed controller when disturbances and uncertainties are introduced into the system.
PubDate: 2023-09-01
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- A Multi-Yield-Surface Plasticity State-Based Peridynamics Model and its
Applications to Simulations of Ice-Structure Interactions-
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Abstract: Abstract Due to complex mesoscopic and the distinct macroscopic evolution characteristics of ice, especially for its brittle-to-ductile transition in dynamic response, it is still a challenging task to build an accurate ice constitutive model to predict ice loads during ship-ice collision. To address this, we incorporate the conventional multi-yield-surface plasticity model with the state-based peridynamics to simulate the stress and crack formation of ice under impact. Additionally, we take into account of the effects of inhomogeneous temperature distribution, strain rate, and pressure sensitivity. By doing so, we can successfully predict material failure of isotropic freshwater ice,iceberg ice, and columnar saline ice. Particularly, the proposed ice constitutive model is validated through several benchmark tests, and proved its applicability to model ice fragmentation under impacts, including drop tower tests and ballistic problems. Our results show that the proposed approach provides good computational performance to simulate ship-ice collision.
PubDate: 2023-09-01
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- Safety-Certificated Line-of-Sight Guidance of Unmanned Surface Vehicles
for Straight-Line Following in a Constrained Water Region Subject to Ocean
Currents-
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Abstract: Abstract The collision-free straight-line following of an unmanned surface vehicle (USV) moving in a constrained water region subject to stationary and moving obstacles is addressed in this paper. USV systems are normally subjected to surge velocity constraints, yaw rate constraints, and unknown ocean currents. Herein, a safety-certificated line-of-sight (LOS) guidance method is proposed to achieve a constrained straight-line following task. First, an antidisturbance LOS guidance law is designed based on the LOS guidance scheme and an extended state observer. Furthermore, collision avoidance with waterway boundaries and stationary/moving obstacles is encoded in control barrier functions, utilizing which the safety constraints are transformed into input constraints. Finally, safety-certificated guidance signals are obtained by solving a quadratic programming problem subject to input constraints. Using the proposed safety-certified LOS guidance method, the USV can accomplish a straight-line following task with guaranteed input-to-state safety. Simulation results substantiate the efficacy of the proposed safety-certificated LOS guidance method for the straight-line following of USVs moving in a constrained water region subject to unknown ocean currents.
PubDate: 2023-09-01
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- Scale Effect of a Kappel Tip-Rake Propeller
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Abstract: Abstract In this paper, the scale effect of Kappel tip-rake propellers with different end plate designs was studied using computational fluid dynamics. Given the base size of the mesh and the appropriate numerical model for the determined simulation, the open-water performance of three Kappel propellers with different bending degrees of the end plate at different scales was calculated. Comparing the scale effect of these propellers, the scale effect of the torque coefficient of a Kappel propeller is more intense than that of the conventional propeller. In addition, the scale effect of the torque coefficient is strong when the bending degree of the end plate increases, dwarfing the scale effect on the thrust coefficient. Following the research on the scale effect of the wake field for the Kappel propeller, the laws that reveal the influence of the scale on the wake field were summarized; that is, the high-speed zone in the wake relatively expands with the increase of the scale in company with a trend of tip cross flow. The research reveals the basic variation trend and rule of the open-water performance and wake distribution for the Kappel propeller under different scales within the Reynolds number range of 4.665×105−8.666×107 considering γ transition, as well as the characteristic differences between the Kappel propellers with different end plate designs, which will be of great significance to its optimization design and application to marine vehicles of different scales.
PubDate: 2023-09-01
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