Subjects -> ENERGY (Total: 414 journals)
    - ELECTRICAL ENERGY (12 journals)
    - ENERGY (252 journals)
    - ENERGY: GENERAL (7 journals)
    - NUCLEAR ENERGY (40 journals)
    - PETROLEUM AND GAS (58 journals)
    - RENEWABLE ENERGY (45 journals)

ENERGY (252 journals)                  1 2 | Last

Showing 1 - 200 of 406 Journals sorted by number of followers
Energy Policy     Partially Free   (Followers: 77)
IET Power Electronics     Open Access   (Followers: 69)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 55)
IEEE Transactions on Power Systems     Hybrid Journal   (Followers: 48)
Energy     Partially Free   (Followers: 41)
Journal of Physical Chemistry C     Hybrid Journal   (Followers: 37)
Nature Energy     Hybrid Journal   (Followers: 37)
International Journal of Hydrogen Energy     Partially Free   (Followers: 35)
IEEE Power and Energy     Full-text available via subscription   (Followers: 34)
Applied Energy     Partially Free   (Followers: 32)
Energy & Fuels     Hybrid Journal   (Followers: 29)
Solar Energy Materials and Solar Cells     Hybrid Journal   (Followers: 29)
Advances in High Energy Physics     Open Access   (Followers: 26)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 26)
Energy & Environment     Hybrid Journal   (Followers: 25)
Energy and Power Engineering     Open Access   (Followers: 23)
International Journal of Turbomachinery, Propulsion and Power     Open Access   (Followers: 22)
Applied Solar Energy     Hybrid Journal   (Followers: 21)
International Journal of Alternative Propulsion     Hybrid Journal   (Followers: 21)
Solar Energy     Hybrid Journal   (Followers: 20)
Energy Materials : Materials Science and Engineering for Energy Systems     Hybrid Journal   (Followers: 19)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 19)
Water International     Hybrid Journal   (Followers: 19)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 18)
Energy and Power     Open Access   (Followers: 18)
IEEE Transactions on Energy Conversion     Hybrid Journal   (Followers: 16)
Nuclear Engineering and Design     Hybrid Journal   (Followers: 16)
Energy, Sustainability and Society     Open Access   (Followers: 16)
Economics and Policy of Energy and the Environment     Full-text available via subscription   (Followers: 16)
Energy Conversion and Management     Hybrid Journal   (Followers: 15)
Progress in Energy and Combustion Science     Hybrid Journal   (Followers: 14)
Waste Management     Hybrid Journal   (Followers: 14)
Energy and Environment Research     Open Access   (Followers: 14)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 14)
Advances in Energy and Power     Open Access   (Followers: 14)
Surface Science Reports     Full-text available via subscription   (Followers: 13)
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 13)
Energy Journal The     Hybrid Journal   (Followers: 13)
Energy Research & Social Science     Full-text available via subscription   (Followers: 13)
Energy and Buildings     Hybrid Journal   (Followers: 12)
International Journal of Sustainable Energy     Hybrid Journal   (Followers: 12)
Oil and Gas Journal     Full-text available via subscription   (Followers: 12)
Biofuels     Hybrid Journal   (Followers: 12)
Journal of Solar Energy     Open Access   (Followers: 12)
Journal of Renewable Energy     Open Access   (Followers: 12)
Advances in Building Energy Research     Hybrid Journal   (Followers: 11)
Energy Systems     Hybrid Journal   (Followers: 11)
International Journal of Thermodynamics     Open Access   (Followers: 11)
Joule     Hybrid Journal   (Followers: 11)
IEEE Transactions on Nuclear Science     Hybrid Journal   (Followers: 10)
Innovations : Technology, Governance, Globalization     Hybrid Journal   (Followers: 10)
International Journal of Energy Research     Hybrid Journal   (Followers: 10)
Energy Efficiency     Hybrid Journal   (Followers: 10)
Journal of Ocean and Climate     Open Access   (Followers: 10)
Energy Science and Technology     Open Access   (Followers: 10)
Energy Strategy Reviews     Open Access   (Followers: 10)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Batteries     Open Access   (Followers: 10)
ACS Energy Letters     Hybrid Journal   (Followers: 10)
Archives of Thermodynamics     Open Access   (Followers: 9)
Journal of Modern Power Systems and Clean Energy     Open Access   (Followers: 9)
International Journal of Global Energy Issues     Hybrid Journal   (Followers: 8)
International Journal of Green Energy     Hybrid Journal   (Followers: 8)
Smart Grid and Renewable Energy     Open Access   (Followers: 8)
Wiley Interdisciplinary Reviews : Energy and Environment     Hybrid Journal   (Followers: 8)
International Journal of Energy and Power     Open Access   (Followers: 8)
American Journal of Energy Research     Open Access   (Followers: 8)
CERN courier. International journal of high energy physics     Free   (Followers: 8)
Energy and Environment Focus     Free   (Followers: 8)
Annals of Nuclear Energy     Hybrid Journal   (Followers: 7)
Fuel and Energy Abstracts     Full-text available via subscription   (Followers: 7)
International Journal of Electric and Hybrid Vehicles     Hybrid Journal   (Followers: 7)
Applied Nanoscience     Open Access   (Followers: 7)
Environmental Progress & Sustainable Energy     Hybrid Journal   (Followers: 7)
Energy Storage Materials     Full-text available via subscription   (Followers: 7)
ACS Applied Energy Materials     Hybrid Journal   (Followers: 7)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 6)
Energy Prices and Taxes     Full-text available via subscription   (Followers: 6)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Computational Water, Energy, and Environmental Engineering     Open Access   (Followers: 6)
Materials for Renewable and Sustainable Energy     Open Access   (Followers: 6)
Energy Science & Engineering     Open Access   (Followers: 6)
American Journal of Energy and Environment     Open Access   (Followers: 6)
Atomic Energy     Hybrid Journal   (Followers: 5)
Carbon Management     Open Access   (Followers: 5)
Journal of Energy Technologies and Policy     Open Access   (Followers: 5)
Energy Studies Review     Open Access   (Followers: 5)
Energy Technology     Partially Free   (Followers: 5)
Geothermal Energy     Open Access   (Followers: 5)
Frontiers in Energy Research     Open Access   (Followers: 5)
Journal of Energy, Environment & Carbon Credits     Full-text available via subscription   (Followers: 5)
International Journal of Sustainable Energy Planning and Management     Open Access   (Followers: 5)
Energy and Environmental Engineering     Open Access   (Followers: 5)
Energy Reports     Open Access   (Followers: 5)
Journal of Energy & Natural Resources Law     Hybrid Journal   (Followers: 5)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Frontiers in Energy     Hybrid Journal   (Followers: 4)
International Journal of Nuclear Energy Science and Technology     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology B: Biology     Hybrid Journal   (Followers: 4)
Wind Energy     Hybrid Journal   (Followers: 4)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 4)
Dams and Reservoirs     Hybrid Journal   (Followers: 4)
Journal of Nano Energy and Power Research     Full-text available via subscription   (Followers: 4)
International Journal of Energy and Environmental Engineering     Open Access   (Followers: 4)
Science and Technology for Energy Transition     Open Access   (Followers: 4)
International Journal of Applied Power Engineering     Open Access   (Followers: 4)
Development of Energy Science     Open Access   (Followers: 4)
Journal of International Energy Policy     Open Access   (Followers: 4)
Foundations and Trends® in Renewable Energy     Full-text available via subscription   (Followers: 4)
International Journal of Energy and Statistics     Hybrid Journal   (Followers: 4)
Sustainable Energy, Grids and Networks     Hybrid Journal   (Followers: 4)
Journal of Energy Chemistry     Full-text available via subscription   (Followers: 4)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Energy, Mechanical, Material and Manufacturing Engineering     Open Access   (Followers: 4)
Journal of Fusion Energy     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Global Energy Law and Sustainability     Hybrid Journal   (Followers: 3)
Science and Technology of Nuclear Installations     Open Access   (Followers: 3)
Power Technology and Engineering     Hybrid Journal   (Followers: 3)
Functional Materials Letters     Hybrid Journal   (Followers: 3)
Distributed Generation & Alternative Energy Journal     Hybrid Journal   (Followers: 3)
Sustainable Energy     Open Access   (Followers: 3)
Journal of Technology Innovations in Renewable Energy     Hybrid Journal   (Followers: 3)
Journal of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 3)
International Journal of Coal Science & Technology     Open Access   (Followers: 3)
Energy and Emission Control Technologies     Open Access   (Followers: 3)
Asian Bulletin of Energy Economics and Technology     Open Access   (Followers: 3)
Protection and Control of Modern Power Systems     Open Access   (Followers: 3)
Sustainable Energy & Fuels     Hybrid Journal   (Followers: 3)
International Journal of Nuclear Knowledge Management     Hybrid Journal   (Followers: 2)
Progress in Nuclear Energy     Hybrid Journal   (Followers: 2)
Electricity Journal     Hybrid Journal   (Followers: 2)
Proceedings of the Institution of Civil Engineers - Energy     Hybrid Journal   (Followers: 2)
Gcb Bioenergy     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
EPJ Photovoltaics     Open Access   (Followers: 2)
International Journal of Clean Coal and Energy     Open Access   (Followers: 2)
Washington and Lee Journal of Energy, Climate, and the Environment     Open Access   (Followers: 2)
Journal of Energy in Southern Africa     Open Access   (Followers: 2)
Journal of Alternate Energy Sources & Technologies     Full-text available via subscription   (Followers: 2)
Journal of Nuclear Energy Science & Power Generation Technology     Hybrid Journal   (Followers: 2)
Nigerian Journal of Technological Research     Full-text available via subscription   (Followers: 2)
Journal of Energy     Open Access   (Followers: 2)
Energy Technology & Policy     Open Access   (Followers: 2)
Biofuel Research Journal     Open Access   (Followers: 2)
Green Energy & Environment     Open Access   (Followers: 2)
Materials Today Energy     Hybrid Journal   (Followers: 2)
Journal of Power and Energy Engineering     Open Access   (Followers: 2)
Clean Energy     Open Access   (Followers: 2)
Global Challenges     Open Access   (Followers: 2)
Carbon Resources Conversion     Open Access   (Followers: 2)
IET Smart Grid     Open Access   (Followers: 2)
IET Energy Systems Integration     Open Access   (Followers: 2)
International Journal of Nuclear Desalination     Hybrid Journal   (Followers: 1)
International Journal of Nuclear Hydrogen Production and Applications     Hybrid Journal   (Followers: 1)
Radioprotection     Hybrid Journal   (Followers: 1)
Nuclear Law Bulletin     Full-text available via subscription   (Followers: 1)
International Journal of Power and Energy Conversion     Hybrid Journal   (Followers: 1)
Clefs CEA     Full-text available via subscription   (Followers: 1)
Journal of Computational Multiphase Flows     Open Access   (Followers: 1)
Natural Resources     Open Access   (Followers: 1)
Journal of Sustainable Bioenergy Systems     Full-text available via subscription   (Followers: 1)
Open Journal of Energy Efficiency     Open Access   (Followers: 1)
Michigan Journal of Sustainability     Open Access   (Followers: 1)
Technology Audit and Production Reserves     Open Access   (Followers: 1)
Sustainable Energy Technologies and Assessments     Full-text available via subscription   (Followers: 1)
International Journal of Smart Grid and Green Communications     Hybrid Journal   (Followers: 1)
Clean Technologies     Open Access   (Followers: 1)
Energy Conversion and Management : X     Open Access   (Followers: 1)
Technology and Economics of Smart Grids and Sustainable Energy     Hybrid Journal   (Followers: 1)
Energy, Ecology and Environment     Hybrid Journal   (Followers: 1)
International Journal of Energy and Water Resources     Hybrid Journal  
BioPhysical Economics and Resource Quality     Hybrid Journal  
Geomechanics and Geophysics for Geo-Energy and Geo-Resources     Hybrid Journal  
BMC Energy     Open Access  
Journal of Energy and Environment Technology of Graduate School Siam Technology College     Open Access  
Global Energy Interconnection     Open Access  
Journal of Energy Systems     Open Access  
International Journal of Energy & Engineering Sciences     Open Access  
International Journal of Energy and Smart Grid     Open Access  
Turkish Journal of Energy Policy     Open Access  
Energy Informatics     Open Access  
High Voltage     Open Access  
Geomechanics for Energy and the Environment     Full-text available via subscription  
ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations     Open Access  
Journal of China Coal Society     Open Access  
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Universal Journal of Applied Science     Open Access  
Ingeniería Energética     Open Access  
E3S Web of Conferences     Open Access  
International Journal of Ambient Energy     Hybrid Journal  
CT&F - Ciencia, Tecnología y Futuro     Open Access  
Multequina     Open Access  
South Pacific Journal of Natural and Applied Sciences     Hybrid Journal  
Chain Reaction     Full-text available via subscription  
Wind Engineering     Hybrid Journal  
Nuclear Data Sheets     Full-text available via subscription  
International Journal of Nuclear Governance, Economy and Ecology     Hybrid Journal  

        1 2 | Last

Similar Journals
Journal Cover
International Journal of Turbomachinery, Propulsion and Power
Number of Followers: 22  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2504-186X
Published by MDPI Homepage  [258 journals]
  • IJTPP, Vol. 9, Pages 1: Effect of Leading-Edge Erosion on the Performance
           of Transonic Compressor Blades

    • Authors: Alexander Hergt, Tobias Danninger, Joachim Klinner, Sebastian Grund, Manfred Beversdorff, Christian Werner-Spatz
      First page: 1
      Abstract: In this paper, an experimental and numerical investigation of the effect of leading-edge erosion in transonic blades was performed. The measurements were carried out on a linear blade cascade in the Transonic Cascade Wind Tunnel of DLR in Cologne at two operating points with an inflow Mach number of 1.05 and 1.12. The numerical simulations were performed by ANSYS Germany. The type and specifications of the erosion for the study were derived from real engine blades and applied to the leading edges of the experimental cascade blades using a waterjet process, as well as modeled in detail and meshed within the numerical setup. Numerical simulations and extensive wake measurements were carried out on the cascades to evaluate the aerodynamic performance. The increase in losses was quantified to be 4 percent, and a reduction in deflection and a rise in pressure were detected at both operating points.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-01-09
      DOI: 10.3390/ijtpp9010001
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 2: Comparison Study of the k − kL −
           ω and γ − Reθ Transition Model in the Open-Water
           Performance Prediction of a Rim-Driven Thruster

    • Authors: Bao Liu, Maarten Vanierschot, Frank Buysschaert
      First page: 2
      Abstract: The present work examines the capabilities of two transition models implemented in ANSYS Fluent in the open-water performance prediction of a rim-driven thruster (RDT). The adopted models are the three-equation k−kL−ω and the four-equation γ−Reθ models. Both of them are firstly tested on a ducted propeller. The numerical results are compared with available experimental data, and a good correlation is found for both models. The simulations employing two transition models are then carried out on a four-bladed rim-driven thruster model and the results are compared with the SST k−ω turbulence model. It is observed that the streamline patterns on the blade surface are significantly different between the transition and fully turbulent models. The transition models can reveal the laminar region on the blade while the fully turbulent model assumes the boundary layer is entirely turbulent, resulting in a considerable difference in torque prediction. It is noted that unlike the fully turbulent model, the transition models are quite sensitive to the free-stream turbulence quantities such as turbulent intensity and turbulent viscosity ratio, as these quantities determine the onset of the transition process. The open-water performance of the studied RDT and resolved flow field are also presented and discussed.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-01-09
      DOI: 10.3390/ijtpp9010002
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 3: An Experimental Database for the Analysis of
           Bursting of a Laminar Separation Bubble

    • Authors: Matteo Dellacasagrande, Davide Lengani, Daniele Simoni, Marina Ubaldi
      First page: 3
      Abstract: The bursting phenomenon consists in the switch of a laminar separation bubble from a short to a long configuration. In the former case, reduced effects on profile pressure distribution are typically observed with respect to the attached condition. On the contrary, long bubbles provoke significant variations in the loading coefficient upstream of the separation position, with increased risk of stall of the lifting surfaces. The present work presents an experimental database describing separated boundary layers evolving under different Reynolds numbers, adverse pressure gradients and free-stream turbulence levels. Overall, more than 80 flow conditions were tested concerning short and long bubbles for the characterization of separated flows under turbine-like conditions. Measurements were performed on a flat plate geometry using a fast-response Particle Image Velocimetry (PIV) system. For each flow case, two sets of 6000 flow records were acquired with an acquisition frequency equal to 300 and 1000 Hz. Based on existing criteria for the identification of the bursting phenomenon, the flow cases were clustered in terms of short and long bubble states. Additionally, the kind of instability (i.e., convective or absolute) developing into the separated boundary layer was identified based on flow statistics. The present data captures the existing link between the bursting of a laminar separation bubble and the onset of the absolute instability of the separated shear layer, with stationary vortices forming in the dead air region.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-01-10
      DOI: 10.3390/ijtpp9010003
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 4: Turbulence Measurements Downstream of a Combustor
           

    • Authors: Andrea Notaristefano, Giacomo Persico, Paolo Gaetani
      First page: 4
      Abstract: Turbulence intensity impacts the performance of turbine stages and it is an important inlet boundary condition for CFD computations; the knowledge of its value at the turbine inlet is then of paramount importance. In combustor–turbine interaction experimental studies, combustor simulators replace real combustors and allow for the introduction of flow perturbation at the turbine inlet. Therefore, the turbulence intensity of a combustor simulator used in a wide experimental campaign at Politecnico di Milano is characterized using a hot-wire probe in a blow-down wind tunnel, and the results are compared to URANS CFD computations. This combustor simulator can generate a combination of a swirl profile with a steady/unsteady temperature disturbance. In the cold unsteady disturbance case, hot-wire measurements are phase-averaged at the frequency of the injected perturbation. The combustor simulator turbulence intensity is measured at two different axial positions to understand its evolution.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-01-10
      DOI: 10.3390/ijtpp9010004
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 5: Design of a 130 MW Axial Turbine Operating with a
           Supercritical Carbon Dioxide Mixture for the SCARABEUS Project

    • Authors: Abdelrahman S. Abdeldayem, Salma I. Salah, Omar A. Aqel, Martin T. White, Abdulnaser I. Sayma
      First page: 5
      Abstract: Supercritical carbon dioxide (sCO2) can be mixed with dopants such as titanium tetrachloride (TiCl4), hexafluoro-benzene (C6F6), and sulphur dioxide (SO2) to raise the critical temperature of the working fluid, allowing it to condense at ambient temperatures in dry solar field locations. The resulting transcritical power cycles have lower compression work and higher thermal efficiency. This paper presents the aerodynamic flow path design of a utility-scale axial turbine operating with an 80–20% molar mix of CO2 and SO2. The preliminary design is obtained using a mean line turbine design method based on the Aungier loss model, which considers both mechanical and rotor dynamic criteria. Furthermore, steady-state 3D computational fluid dynamic (CFD) simulations are set up using the k-ω SST turbulence model, and blade shape optimisation is carried out to improve the preliminary design while maintaining acceptable stress levels. It was found that increasing the number of stages from 4 to 14 increased the total-to-total efficiency by 6.3% due to the higher blade aspect ratio, which reduced the influence of secondary flow losses, as well as the smaller tip diameter, which minimised the tip clearance losses. The final turbine design had a total-to-total efficiency of 92.9%, as predicted by the CFD results, with a maximum stress of less than 260 MPa and a mass flow rate within 1% of the intended cycle’s mass flow rate. Optimum aerodynamic performance was achieved with a 14-stage design where the hub radius and the flow path length are 310 mm and 1800 mm, respectively. Off-design analysis showed that the turbine could operate down to 88% of the design reduced mass flow rate with a total-to-total efficiency of 80%.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-02-02
      DOI: 10.3390/ijtpp9010005
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 6: Genetic Algorithm-Based Optimisation of a
           Double-Wall Effusion Cooling System for a High-Pressure Turbine Nozzle
           Guide Vane

    • Authors: Michael van de Noort, Peter T. Ireland
      First page: 6
      Abstract: Double-Wall Effusion Cooling schemes present an opportunity for aeroengine designers to achieve high overall cooling effectiveness and convective cooling efficiency in High-Pressure Turbine blades with reduced coolant usage compared to conventional cooling technologies. This is accomplished by combining impingement, pin-fin and effusion cooling. Optimising these cooling schemes is crucial to ensuring that cooling is achieved sufficiently at high-heat-flux regions and not overused at low-heat-flux ones. Due to the high number of design variables employed in these systems, optimisation through the use of Computational Fluid Dynamics (CFD) simulations can be a computationally costly and time-consuming process. This study makes use of a Low-Order Flow Network Model (LOM), developed, validated and presented previously, which quickly assesses the pressure, temperature, mass flow and heat flow distributions through a Double-Wall Effusion Cooling scheme. Results generated by the LOM are used to rapidly produce an ideal cooling system design through the use of an Evolutionary Genetic Algorithm (GA) optimisation process. The objective is to minimise the coolant mass flow whilst maintaining acceptable metal cooling effectiveness around the external surface of the blade and ensuring that the Backflow Margin for all film holes is above a selected threshold. For comparison, a Genetic Aggregation model-based optimisation using CFD simulations in ANSYS Workbench is also conducted. Results for both the reduction of coolant mass flow and the total optimisation runtime are analysed alongside those from the LOM, demonstrating the benefit of rapid low-order solving techniques.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-02-02
      DOI: 10.3390/ijtpp9010006
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 9, Pages 7: Multidisciplinary Automation in Design of Turbine
           Vane Cooling Channels

    • Authors: Sanjay Nambiar, Anan Ashrabi Ananno, Herman Titus, Anton Wiberg, Mehdi Tarkian
      First page: 7
      Abstract: In the quest to enhance the efficiency of gas turbines, there is a growing demand for innovative solutions to optimize high-pressure turbine blade cooling. However, the traditional methods for achieving this optimization are known for their complexity and time-consuming nature. We present an automation framework to streamline the design, meshing, and structural analysis of cooling channels, achieving design automation at both the morphological and topological levels. This framework offers a comprehensive approach for evaluating turbine blade lifetime and enabling multidisciplinary design analyses, emphasizing flexibility in turbine cooling design through high-level CAD templates and knowledge-based engineering. The streamlined automation process, supported by a knowledge base, ensures continuity in both the mesh and structural simulation automations, contributing significantly to advancements in gas turbine technology.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2024-02-19
      DOI: 10.3390/ijtpp9010007
      Issue No: Vol. 9, No. 1 (2024)
       
  • IJTPP, Vol. 8, Pages 36: Impact of Unsteady Wakes on the Secondary Flows
           of a High-Speed Low-Pressure Turbine Cascade

    • Authors: Gustavo Lopes, Loris Simonassi, Sergio Lavagnoli
      First page: 36
      Abstract: The aerodynamics of a high-speed low-pressure turbine (LPT) cascade were investigated under steady and unsteady inlet flows. The tests were performed at outlet Mach (M) and Reynolds numbers (Re) of 0.90 and 70k, respectively. Unsteady wakes were simulated by means of a wake generator equipped with bars. A bar reduced frequency (f+) of ∼0.95 was used for the unsteady case. The inlet flow field was characterized in terms of the total pressure profile and incidence. The blade aerodynamics at midspan and the secondary flow region were investigated by means of pneumatic taps and hot-film sensors. The latter provided a novel view into the impact of the secondary flows on the heat transfer topology on the blade suction side (SS). The cascade performance was quantified in terms of the outlet flow angle and losses by means of a directional multi-hole probe. The results report the phase-averaged impact of unsteady wakes on the secondary flow structures in an open test case high-speed LPT geometry.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-22
      DOI: 10.3390/ijtpp8040036
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 37: Effect of Mistuning and Blade Passing Frequencies
           on a Turbine’s Integral Mode Blade Vibration Detection Using a
           Pulsation Probe

    • Authors: Takashi Ando
      First page: 37
      Abstract: For engines operating using heavy fuel oil (HFO), the nozzle rings of turbocharger turbines are prone to severe degradation because of contamination with unburned fuel deposits. This contamination may lead to increased excitation of blade resonance. A previous study provides technical guidelines on how to extract the relevant information from pulsation spectra using a single probe installed away from the turbine trailing edge and some sound experimental proofs of integral mode turbine vibration detection. These theoretical discussions only allude to the effects of mistuning and interferences due to classical blade passing frequencies on sound radiation patterns emitted by integral blade vibration modes. In this study, both effects are thoroughly discussed. Combining the knowledge of theoretical study and further experimental results, the application range of this blade vibration detection method can be remarkably extended.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-02
      DOI: 10.3390/ijtpp8040037
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 38: Transient Resonance Passage of a Mistuned Bladed
           Disk with and without Underplatform Dampers

    • Authors: Katharina Brinkmann, Thomas Hoffmann, Lars Panning-von Scheidt, Heinrich Stüer
      First page: 38
      Abstract: In this work, the vibration response of an academic free-standing turbine blisk is analyzed in regard to transient resonance passages. Measurement data are recorded using strain gauges and tip timing to evaluate the blades first bending mode both linearly and with two different types of underplatform dampers. These results are validated against steady-state responses and show good agreement with each other. To examine the effects of a transient resonance passage, response functions of each blade are evaluated both with and without the underplatform dampers. It is shown that friction damping is able to inhibit any appearance of a transient ring-down. Additionally, a multi-mass oscillator model with frictional contacts is analyzed, which qualitatively exhibits the same dynamics as the measurements. Due to geometric mistuning, all blades exhibit different vibration responses. This can lead to a transient amplitude amplification, which is observed on several blades. Analogously, this phenomenon can be mitigated by friction damping.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-02
      DOI: 10.3390/ijtpp8040038
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 39: Systematic Comparison of Sensor Signals for Pump
           Operating Points Estimation Using Convolutional Neural Network

    • Authors: Hanbing Ma, Oliver Kirschner, Stefan Riedelbauch
      First page: 39
      Abstract: The head and flow rate of a pump characterize the pump performance, which help determine whether maintenance is needed. In the proposed method, instead of a traditional flowmeter and manometer, the operating points are identified using data collected from accelerometers and microphones. The dataset is created from a test rig consisting of a standard centrifugal water pump and measurement system. After implementing preprocessing techniques and Convolutional Neural Networks (CNNs), the trained models are obtained and evaluated. The influence of the sensor location and the performance of different signals or signal combinations are investigated. The proposed method achieves a mean relative error of 7.23% for flow rate and 2.37% for head with the best model. By employing two data augmentation techniques, performance is further improved, resulting in a mean relative error of 3.55% for flow rate and 1.35% for head with the sliding window technique.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-04
      DOI: 10.3390/ijtpp8040039
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 40: New Supersonic Nozzle Test Rig Used to Generate
           Condensing Flow Test Data According to Barschdorff

    • Authors: Manuel Ernesto Maqueo Martínez, Stefan Schippling, Markus Schatz, Damian M. Vogt
      First page: 40
      Abstract: Considerable progress has been achieved in recent decades in understanding the phenomena related to the onset of condensation in steam flows, both experimentally and especially numerically. Nevertheless, there is still a certain disagreement between the different numerical models used. Unfortunately, the available experimental validation data are not sufficiently detailed to allow for proper validation of computational fluid dynamics (CFD) simulations. Therefore, this paper presents new experimental data for condensing steam flows, acquired in a supersonic nozzle according to Barschdorff, at the Institute of Thermal Turbomachinery Laboratory (ITSM) at the University of Stuttgart. A steady inlet pressure of approximately 784 mbar was set for three inlet temperatures down to 100.2 ∘C. Condensation onset is accurately captured across the nozzle, using down to 1 mm spatial resolution for both pneumatic and light spectra measurements. CFD simulations were performed using the commercial solver ANSYS CFX. The droplet diameters are numerically overestimated by approximately a factor of 1.5. Disagreement has been found between original Barschdorff’s experiments and measurements at ITSM. However, there is a good agreement in terms of the pressure distribution along the nozzle axis between experimental and numerical results. The reproducibility of the results is excellent.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-04
      DOI: 10.3390/ijtpp8040040
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 41: Adjoint-Based Design Optimization of a Volute for
           a Radial Compressor

    • Authors: Romain Hottois, Arnaud Châtel, Tom Verstraete
      First page: 41
      Abstract: Numerical optimization methods are widely used for designing turbomachinery components due to the cost and time savings they can provide. In the available literature, the shape optimization of radial compressors mainly focuses on improving the impeller alone. However, it is well-established knowledge that the volute plays a key role in the overall performance of the compressor. The aim of the present paper is to perform an adjoint-based optimization of a volute that is designed for the SRV2-O compressor. The CAD model was first created by using the parametrization of 33 design parameters. Then, a butterfly topology was applied to mesh the computational domain with a multi-block structured grid, and an elliptic smoothing procedure was used to improve the quality of the fluid grid. A steady-state RANS CFD solver with a Spalart-Allmaras turbulence model was used to solve the Navier–Stokes equations, and then the flow sensitivities were computed with an adjoint solver. The objective function consists of minimizing the loss coefficient of the volute. The optimization is performed to obtain an improved design with a 14% loss reduction. A detailed flow and design analysis is carried out to highlight the loss reduction mechanisms, followed by the optimizer. Finally, the compressor map of the full stage is compared between the baseline and the optimized volute from the CFD simulations using a mixing plane interface. This research demonstrates the successful use of a gradient-based optimization technique to improve the volute of a radial compressor and opens the door towards simultaneously optimizing the wheel and the volute.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-13
      DOI: 10.3390/ijtpp8040041
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 42: State of the Art on Two-Phase Non-Miscible
           Liquid/Gas Flow Transport Analysis in Radial Centrifugal Pumps Part B:
           Review of Experimental Investigations

    • Authors: Michael Mansour, Dominique Thévenin
      First page: 42
      Abstract: This paper aims to summarize the results of several experimental investigations regarding two-phase liquid–gas flows in radial centrifugal pumps. The main objective is to combine the corresponding experimental results and collect the obtained knowledge to provide a better understanding of this configuration. The simultaneous transport of the two phases, the phase segregation, and the regions of safe or critical pump performance were described for a wide variety of pump configurations. This review covers single- and two-phase pumping conditions, performance degradation, pump breakdown, performance hysteresis, different flow regimes, flow regime maps, flow instabilities, and surging. This manuscript also considers the influence of employing different pump configurations on pump performance and flow regimes. This includes comparisons between closed and semi-open impellers, standard and increased tip clearance gaps, and running the pump with and without an inducer. Many of the results discussed have been published in a series of research papers. They were all collected, summarized, and compared systematically in the present review.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-13
      DOI: 10.3390/ijtpp8040042
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 43: Surrogate Modeling of the Aeroacoustics of an
           NM80 Wind Turbine

    • Authors: Filippo De Girolamo, Lorenzo Tieghi, Giovanni Delibra, Valerio Francesco Barnabei, Alessandro Corsini
      First page: 43
      Abstract: Wind turbines play a major role in the European Green Deal for clean energy transition. Noise is a critical aspect among open technological issues, as it determines the possibility of onshore installations near inhabited places and the possible detrimental effects on wildlife when offshore. This paper assesses the accuracy of different approaches to predicting the sound pressure level (SPL) of a wind turbine. The 2.75 MW Neg Micon NM80 horizontal axis wind turbine (HWAT) was simulated in OpenFOAM, modeling the turbine with the actuator line method (ALM) implemented in the turbinesFoam library. Two different inflow conditions were considered: a stationary inflow with a typical atmospheric boundary layer profile and a time-dependent inflow derived from a precursor channel with fully turbulent conditions. The surrogate model for noise prediction used for this work is based on the synthetic/surrogate acoustics models (SAMs) of Amiet and Brooks-Pope-Marcolini (BPM). This approach allows for blade motion modeling and the prediction of the SPL of the URANS postprocessing results. The SPL spectrum obtained was then compared to the results from the other aeroacoustic solvers of IEA Task 39 participants, showing the best performance in the fully turbulent case. The results demonstrate that coupling between the ALM and surrogate acoustics provides more accurate results than the blade element momentum (BEM) approach.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-10-20
      DOI: 10.3390/ijtpp8040043
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 44: Steady and Unsteady Numerical Characterization of
           the Secondary Flow Structures of a Highly Loaded Low-Pressure Compressor
           Stage

    • Authors: Riccardo Toracchio, Fabrizio Fontaneto, Koen Hillewaert
      First page: 44
      Abstract: This paper presents the numerical characterization of a highly loaded compressor by means of 3D unsteady RANS simulations. The focus is on critical flow structures and their evolution at different operating points of the machine. First, the numerical setup and mesh quality are presented to support the reliability of the provided results. The comparison against experiments is then described for this purpose. Later, a full description of the unsteady behavior of the machine is provided, giving special attention to the two regions where the most critical features are expected: the rotor hub wall and the casing. Rotor–stator interactions are then investigated and the role of the inlet guide vane (IGV) is finally discussed. Results are analyzed at design and near-stall conditions, with a focus on the behavior close to the stability limit at 100% speed.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-11-10
      DOI: 10.3390/ijtpp8040044
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 45: Lubrication Film Friction Model for Grooved
           Annular Seals

    • Authors: Robin M. Robrecht, Peter F. Pelz
      First page: 45
      Abstract: Grooved liquid annular seals have a significant influence on the design of turbomachines. Corresponding lubrication film models need to account for the different friction behavior of the grooves compared to plain seals. However, there is a lack of reliable and validated models for this purpose. Thus, the applicability of a friction factor model is explored and a calibration method is presented. A single square groove is investigated by means of 96 steady-state RANS simulations for different operation conditions and groove geometries. The results are used to calibrate the friction model and successfully verify it in terms of the pressure drop over the groove. For validation, two full grooved seals with relatively large square grooves were investigated by experiment. The friction model was incorporated in a lubrication model and compared to the measurement data for the pressure difference and the resulting force for specified leakage and eccentricity. The model predictions for the pressure difference can be considered very good. The force predictions show significant deviation, but can be considered acceptable given the low force magnitudes and measurement uncertainty. The results offer a general validity to our friction model approach, assumptions and the calibration method.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-11-10
      DOI: 10.3390/ijtpp8040045
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 46: Unsteady Cavitation Analysis of the Centrifugal
           Pump Based on Entropy Production and Pressure Fluctuation

    • Authors: Qiaorui Si, Fanjie Deng, Yu Lu, Minquan Liao, Shouqi Yuan
      First page: 46
      Abstract: A numerical method using combined detached-eddy simulation (DES) and a cavitation model considering the rotation effect is used for unsteady cavitation flow field of the centrifugal pump. A closed-type pump test system was established to obtain the pump performance and pressure pulsation characteristics under different flow rates and cavitation condition, which provide boundary conditions and verification of calculations. Based on the calculation results of the unsteady flow field of the centrifugal pump cavitation, the entropy generation analysis of the flow field and an analysis of the pressure fluctuation characteristics were carried out. Then, we tried to reveal the relationship between cavitation and the deterioration of the centrifugal pump performance and the generation of the unstable operation excitation force. The internal energy loss is mainly concentrated in the impeller, volute, and pump cavity area, which accounts for more than 85% of the total entropy generation. The characteristic frequency of a Strouhal number of about 0.333 appears at the volute tongue due to the cavitation flow spread downstream.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-11-11
      DOI: 10.3390/ijtpp8040046
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 47: The Current Gap between Design Optimization and
           Experiments for Transonic Compressor Blades

    • Authors: Edwin Joseph Munoz Lopez, Alexander Hergt, Till Ockenfels, Sebastian Grund, Volker Gümmer
      First page: 47
      Abstract: The successful design of compressor blades through numerical optimization relies on accurate CFD-RANS solvers that are able to capture the general performance of a given design candidate. However, this is a difficult task to achieve in transonic flow conditions, where the flow is dominated by inherently unsteady shock effects. In order to assess the current gap between numerics and experiments, the DLR has tested the recently optimized Transonic Cascade TEAMAero at the transonic cascade wind tunnel. The tests were performed at a Mach number of 1.2 and with inflow angles between 145 and 147. The results indicate satisfactory agreement across the expected working range, over which the cascade losses were consistently predicted within a 3–6% error. However, some key differences are observed in the details of the wake and in the performance near the endpoints of the working range. This comparison helps validate the design process but also informs its constraints based on the limitations of CFD-RANS solvers.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-11-13
      DOI: 10.3390/ijtpp8040047
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 48: Determination of a Numerical Surge Limit by Means
           of an Enhanced Greitzer Compressor Model

    • Authors: Tobias Haeckel, Dominik Paul, Sebastian Leichtfuß, Heinz-Peter Schiffer, Werner Eißler
      First page: 48
      Abstract: The surge limit of centrifugal compressors is a key parameter in the design process of modern turbochargers. Numerical methods like steady-state simulations are state-of-the-art methods for predicting the performance of the centrifugal compressor. In contrast to that, the determination of the surge limit with any numerical method is still an unsolved challenge. Since the extensive work of Greitzer and many other researchers in this field, it is well-known that surge is a system-dependent phenomenon. In the case of steady-state simulations, the simulation domain is chosen to be as small as possible due to the numerical cost. This simply implies that there is no system information included in the numerical model. Therefore, it is not possible to determine any system-dependent surge limit with today’s applied numerical methods. To overcome this issue, an enhanced Greitzer surge model, which has been developed at Tu Darmstadt, should act as a link between the simulation and the system in which the compressor will be operated. The focus of this paper will rather be on the methodology of determining the surge limit by means of numerical data than on the surge model itself. The methodology will be validated by experimental data of different systems.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-11-14
      DOI: 10.3390/ijtpp8040048
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 49: Experimental and Numerical Investigation of a
           Turbine Vane Frame with Splitters at Different Operating Points

    • Authors: Simon Pramstrahler, Andreas Peters, Mikel Lucas García De Albéniz, Peter Adrian Leitl, Franz Heitmeir, Andreas Marn
      First page: 49
      Abstract: A turbine vane frame is a special type of intermediate turbine duct, and is one option to improve the efficiency and reduce the length and weight of an aero-engine. However, due to its geometry, it features a complex flow field, and therefore in-depth aerodynamic investigations are necessary. Especially for aviation, every component needs to function reliably during all operating points. To perform this study at the Institute for Thermal Turbomachinery at the Graz University of Technology, the Subsonic Test Turbine Facility for Aerodynamic, Aeroacoustic and Aeroelastic Investigations was equipped with a turbine vane frame and a low-pressure turbine located downstream. Measurements were taken with aerodynamic five-hole probes for three operating points, and were compared with steady-state and transient simulations as well as analytic solutions for the pressure drop in the TVF. Finally, the most important loss mechanisms are described.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-01
      DOI: 10.3390/ijtpp8040049
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 50: Effect of Porosity and Injection Ratio on the
           Performance of Transpiration Cooling through Gyroids

    • Authors: Benjamin J. Brimacombe, James A. Scobie, Joseph M. Flynn, Carl M. Sangan, Oliver J. Pountney
      First page: 50
      Abstract: This paper presents experimental measurements of adiabatic effectiveness for three transpiration cooling porosities (ϕ = 0.3, 0.4, and 0.5) constructed from gyroid lattice structures. To the authors’ knowledge, this is the first use of a Triply Periodic Minimal Surface (TPMS) function to produce transpiration test coupons of varying porosity. Polymer gyroid lattice structures were successfully printed using Stereolithography (SLA) down to ϕ = 0.3 for a print resolution of 25 microns and unit cell size of 2 mm. Cooling performance was measured in a small-scale wind tunnel. High-resolution Infrared Thermography was used to determine wall temperatures downstream of the porous section. When tested at both common blowing ratios (M = 0.029, 0.048, and 0.062) and common injection ratios (F = 0.010, 0.017, and 0.022) the cooling performance was found to be dependent on porosity for constant but not for constant F. Having determined F as the more important parameter for comparison, results are presented alongside transpiration and effusion data from literature.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-01
      DOI: 10.3390/ijtpp8040050
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 51: Profile Loss Prediction for Organic Rankine Cycle
           Turbines: An Experimental Case Study

    • Authors: Leander Hake, Stephan Sundermeier, Stefan aus der Wiesche
      First page: 51
      Abstract: The results of profile loss measurements, including trailing edge flow details, are presented for the flow of an organic vapor through a linear turbine cascade. The so-called VKI-I blade profile from the open literature was chosen for the cascade, and the working fluid was NOVEC 649. Pitot probes and hot-wire anemometry were employed to measure the flow field up and downstream of the cascade. Details of the unsteady flow caused by the trailing edge of the blades and the turbulent spectrum were investigated using hot-wire anemometry. The new organic vapor flow results were compared with the literature data obtained for air and with the prediction of conventional literature loss models. It was found that, under certain thermodynamic conditions, specific traditional loss models can reasonably predict organic Rankine cycle (ORC) turbines’ profile loss. Still, significant deviations between the loss models and the experimental data can also occur.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-01
      DOI: 10.3390/ijtpp8040051
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 52: Numerical Modelling of the 3D Unsteady Flow of an
           Inlet Particle Separator for Turboshaft Engines

    • Authors: Marco Castaldi, Ignacio Mayo, Jacques Demolis, Frank Eulitz
      First page: 52
      Abstract: Helicopter and turboprop engines are susceptible to the ingestion of debris and other foreign objects, especially during take-off, landing, and hover. To avoid deleterious effects, filters such as Inlet Particle Separators (IPS) can be installed. However, the performance and limitations of these systems have to be investigated before the actual equipment can be installed in the aircraft powerplant. In this paper, we propose different numerical methods with increasing resolution in order to provide an aerodynamic characterization of the IPS, i.e., from a simple semi-empirical model to 3D large eddy simulation. We validate these numerical tools that could aid IPS design using experimental data in terms of global parameters such as separation efficiency and pressure losses. For each of those tools, we underline weaknesses and potential benefits in industry practices. Unsteady flow analysis reveals that detached eddy simulation is the trade-off choice that allows designers to most effectively plan experimental campaigns and mitigate risks.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-04
      DOI: 10.3390/ijtpp8040052
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 53: Fan Stage Design and Performance Optimization for
           Low Specific Thrust Turbofans

    • Authors: Oliver Sjögren, Tomas Grönstedt, Anders Lundbladh, Carlos Xisto
      First page: 53
      Abstract: In modern turbofan engines, the bypass section of the fan stage alone provides the majority of the total thrust required in cruise, and the size of the fan has a considerable effect on the overall engine weight and nacelle drag. Thrust requirements in different parts of the flight envelope must also be satisfied together with sufficient margins towards stalling. An accurate description of the interdependencies between the relevant performance and design attributes of the fan stage alone—such as efficiency, surge margin, fan-face Mach number, stage loading, flow coefficient, and aspect ratio—are therefore necessary to estimate system-level objectives such as mission fuel burn and the direct operating cost with enough confidence during the conceptual design phase. The contribution of this study is to apply a parametric optimization approach to the conceptual design of fan stages for low specific thrust turbofans based on the streamline curvature method. Trade-offs between fan stage attributes for Pareto-optimal solutions are modeled by training Kriging surrogate models on the results from the parametric optimization. A case study is provided in the end to demonstrate the potential implications of including a higher level of fan-stage parameter interdependency in an engine systems model. Results implied that being able to predict the rotor solidity required to maintain a given average blade loading—in addition to stage efficiency—is of significant importance when it comes to evaluating the trade-off between engine weight and thrust-specific fuel consumption.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-04
      DOI: 10.3390/ijtpp8040053
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 54: NREL-5MW Wind Turbine Noise Prediction by FWH-LES

    • Authors: Claudio Bernardi, Federico Porcacchia, Claudio Testa, Pietro De Palma, Stefano Leonardi, Stefania Cherubini
      First page: 54
      Abstract: This paper deals with large onshore wind turbine aeroacoustics. Noise from the NREL 5 MW device is predicted by the permeable-surface Ffowcs Williams–Hawkings equation (FWH-P), starting from the postprocessing of LES data on different acoustic surfaces S. Their size and placement is aimed at embedding most of the aerodynamic sources of sound surrounding rotor and nacelle. Due to the presence of eddies that inevitably cross S, this paper compares results from open and closed acoustic surfaces, and the outflow disk averaging technique. The issues related to the interpolation process of LES data on S is discussed as well. In order to assess the LES/FWH-P aeroacoustic platform, LES and FWH-P pressures are compared in the very-near field. It is shown that, within the limits of the discretization settings imposed by the interpolation procedure and for the Reynolds number working condition investigated herein, the lack of quadrupole sources outside the permeable surface(s) deeply affect the quality of FWH-P acoustic pressures with respect to direct LES signals.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-06
      DOI: 10.3390/ijtpp8040054
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 55: A Comparison of Steam Turbine Control Valve
           Geometries and Their Dynamic Behavior at Part Load

    • Authors: Christian Windemuth, Martin Lange, Ronald Mailach
      First page: 55
      Abstract: A growing significance of flexible steam turbine operation challenges the control of turbines, as part load operation using control valves can be accompanied by highly unsteady flow conditions. The increased dynamic load induced by pressure forces can reduce the reliable operating range, weaken the valve, and lead to mechanical failures. The geometry of the valve plays a major role in the reduction of dynamic forces. Using a scaled control valve, experiments were conducted with a focus on the dynamic behavior of the valve head. A spherical valve shape favoring unstable operation was used as a reference case, and the desired instability was proven by measurements. Different modified valve geometries based on literature featuring separation edges were then tested against the spherical shape. Results indicate the improved stability of the modified geometries over the reference geometry. For most of the operating range, vibrations were drastically reduced, and the overall flow stabilized.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-12-18
      DOI: 10.3390/ijtpp8040055
      Issue No: Vol. 8, No. 4 (2023)
       
  • IJTPP, Vol. 8, Pages 19: Advanced Gas Turbine Cooling for the
           Carbon-Neutral Era

    • Authors: Kenichiro Takeishi, Robert Krewinkel
      First page: 19
      Abstract: In the coming carbon-neutral era, industrial gas turbines (GT) will continue to play an important role as energy conversion equipment with high thermal efficiency and as stabilizers of the electric power grid. Because of the transition to a clean fuel, such as hydrogen or ammonia, the main modifications will lie with the combustor. It can be expected that small and medium-sized gas turbines will burn fewer inferior fuels, and the scope of cogeneration activities they are used for will be expanded. Industrial gas turbine cycles including CCGT appropriate for the carbon-neutral era are surveyed from the viewpoint of thermodynamics. The use of clean fuels and carbon capture and storage (CCS) will inevitably increase the unit cost of power generation. Therefore, the first objective is to present thermodynamic cycles that fulfil these requirements, as well as their verification tests. One conclusion is that it is necessary to realize the oxy-fuel cycle as a method to utilize carbon-heavy fuels and biomass and not generate NOx from hydrogen combustion at high temperatures. The second objective of the authors is to show the required morphology of the cooling structures in airfoils, which enable industrial gas turbines with a higher efficiency. In order to achieve this, a survey of the historical development of the existing cooling methods is presented first. CastCool® and wafer and diffusion bonding blades are discussed as turbine cooling technologies applicable to future GTs. Based on these, new designs already under development are shown. Most of the impetus comes from the development of aviation airfoils, which can be more readily applied to industrial gas turbines because the operation will become more similar. Double-wall cooling (DWC) blades can be considered for these future industrial gas turbines. It will be possible in the near future to fabricate the DWC structures desired by turbine cooling designers using additive manufacturing (AM). Another conclusion is that additively manufactured DWC is the best cooling technique for these future gas turbines. However, at present, research in this field and the data generated are scattered, and it is not yet possible for heat transfer designers to fabricate cooling structures with the desired accuracy.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-06-24
      DOI: 10.3390/ijtpp8030019
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 20: Aerodynamics and Sealing Performance of the
           Downstream Hub Rim Seal in a High-Pressure Turbine Stage

    • Authors: Filippo Merli, Nicolas Krajnc, Asim Hafizovic, Marios Patinios, Emil Göttlich
      First page: 20
      Abstract: The purpose of the paper is to characterize the aerodynamic behavior of a rotor-downstream hub cavity rim seal in a high-pressure turbine (HPT) stage. The experimental data are acquired in the Transonic Test Turbine Facility at the Graz University of Technology: the test setup includes two engine-representative turbine stages (the last HPT stage and first LPT stage), with the intermediate turbine duct in between. All stator-rotor cavities are supplied with purge flows by a secondary air system, which simulates the bleeding air from the compressor stages of the real engine. The HPT downstream hub cavity is provided with wall taps and pitot tubes at different radial and circumferential locations, which allows the performance of steady pressure and seed gas concentration measurements for different purge mass flows and HPT vanes clocking positions. Moreover, miniaturized pressure transducers are adopted to evaluate the unsteady pressure distribution, and an oil flow visualization is performed to retrieve additional information on the wheel space structures. The annulus pressure asymmetry depends on the HPT vane clocking, but this is shown to have negligible impact on the minimum purge mass flow required to seal the cavity. However, the hub pressure profile drives the distribution of the cavity egress in the turbine channel. The unsteady pressure field is dominated by blade-synchronous oscillations. No non-synchronous components with comparable intensity are detected.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-07-10
      DOI: 10.3390/ijtpp8030020
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 21: Experimental Analysis of the Three Dimensional
           Flow in a Wells Turbine Rotor

    • Authors: Fabio Licheri, Tiziano Ghisu, Francesco Cambuli, Pierpaolo Puddu
      First page: 21
      Abstract: An experimental investigation of the local flow field in a Wells turbine has been conducted, in order to produce a detailed analysis of the aerodynamic characteristics of the rotor and support the search for optimized solutions. The measurements were conducted with a hot-wire anemometer (HWA) probe, reconstructing the local three-dimensional flow field both upstream and downstream of a small-scale Wells turbine. The multi-rotation technique has been applied to measure the three velocity components of the flow field for a fixed operating condition. The results of the investigation show the local flow structures along a blade pitch, highlighting the location and radial extension of the vortices which interact with the clean flow, thus degrading the turbine’s overall performance. Some peculiarities of this turbine have also been shown, and need to be considered in order to propose modified solutions to improve its performance.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-07-16
      DOI: 10.3390/ijtpp8030021
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 22: Performance Evaluation in a Fully Purged
           High-Pressure Turbine Stage Using Seed Gas Concentration Measurements

    • Authors: Filippo Merli, Nicolas Krajnc, Asim Hafizovic, Emil Göttlich
      First page: 22
      Abstract: The efficiency assessment of a high-pressure turbine (HPT) stage is complicated by the presence of upstream and downstream purge flows. In fact, the efficiency calculation is often based on mass flow-averaged values of total temperature at the stage inlet and outlet planes. Moreover, the purge flow distribution in the annulus is usually unknown and therefore assumed to be uniform. This paper presents and applies an alternative method to calculate the efficiency of a fully purged HPT stage. Such a definition relies on seed gas concentration measurements at the HPT stage outlet plane to determine the outlet purge flow distribution. After comparing the alternative method to the standard definition (based on the assumption of uniform purge) for the nominal purge case, the efficiency variation between the case with nominal purge and the case without purge is investigated.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-07-17
      DOI: 10.3390/ijtpp8030022
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 23: Rotor Cascade Assessment at Off-Design Condition:
           An Aerodynamic Investigation on Platform Cooling

    • Authors: Hamed Abdeh, Giovanna Barigozzi, Nicoletta Franchina
      First page: 23
      Abstract: Off-design condition of a rotor blade cascade with and without platform cooling was experimentally investigated. The ability of the gas turbine to operate down to 50% to 20% of its nominal intake air flow rate has an important consequence in the change in the inlet incidence angle, which varied from nominal to −20°. Platform cooling through an upstream slot simulating the stator-to-rotor interface gap was considered. The impact of rotation on purge flow injection was simulated by installing fins inside the slot to give the coolant flow a tangential direction. Aerodynamic measurements to quantify the cascade aerodynamic loss and secondary flow structures were performed at Ma2is = 0.55, varying the coolant to main flow mass flow ratio (MFR%) and the incidence angle. The results show that losses strongly increase with MFR. A negative incidence allows a reduction in the overall loss even when coolant is injected with a high MFR. The more negative the incidence, the greater the loss reduction.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-07-22
      DOI: 10.3390/ijtpp8030023
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 24: Heat Transfer Analysis of Damaged Shrouded
           High-Pressure Turbine Rotor Blades

    • Authors: Mario Carta, Tiziano Ghisu, Shahrokh Shahpar
      First page: 24
      Abstract: Due to the increasingly high turbine inlet temperatures, heat transfer analysis is now, more than ever, a vital part of the design and optimization of high-pressure turbine rotor blades of a modern jet engine. The present study aimed to find out how shape deviation and in-service deterioration affect heat exchange patterns on the rotor blade. The rotor geometries used for this analysis are represented by a set of high-resolution 3D structured light scans of blades with the same number of in-service hours. An automatic meshing technique was employed to generate high-resolution meshes directly on the scanned rotor geometries, which captured all the surface features with high fidelity. Steady-state 3D RANS flow simulations with a k-ω SST turbulence model were conducted on a one-and-a-half stage computational domain of the scanned geometries. First, the distribution of the heat transfer coefficient was calculated for each blade; then, a correlation was sought between the heat transfer coefficient and parametrized shape deviation, to assess the impact of each parameter on HTC levels.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-08-01
      DOI: 10.3390/ijtpp8030024
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 25: Numerical Investigation of Rotating Instability
           Development in a Wide Tip Gap Centrifugal Compressor

    • Authors: Xavier Flete, Nicolas Binder, Yannick Bousquet, Sandrine Cros
      First page: 25
      Abstract: In the current study, full-stage unsteady simulations were performed to investigate rotating instability inception mechanisms in a particularly large tip clearance centrifugal compressor with a vaneless diffuser and a volute. Four operating points along a speed line were analysed to understand the influence of the mass flow reduction on flow structures. Close to the peak efficiency, an unsteady interaction between the tip clearance vortices and splitter blades was observed. Considering other studies, the influence of the tip gap size was analysed. Then, a large-scale vortex shedding from the leading edges of the main blades was detected when the stage operated near the maximum pressure ratio. It was demonstrated that shed vortices were caused by the combination of the radial gradient of the tangential velocity under the tip vortex and the reverse backflow near the casing. Previous studies on axial compressors refer to these vortical structures as backflow vortices. These vortices cause a significant increase in the incidence angle in the tip region.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-08-01
      DOI: 10.3390/ijtpp8030025
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 26: Scale-Resolving Hybrid RANS-LES Simulation of a
           Model Kaplan Turbine on a 400-Million-Element Mesh

    • Authors: Simon Joßberger, Stefan Riedelbauch
      First page: 26
      Abstract: Double-regulated Kaplan turbines with adjustable guide vanes and runner blades offer a high degree of flexibility and good efficiency for a wide range of operating points. However, this also leads to a complex geometry and flow guidance with, for example, vortices of different sizes and strengths. The flow in a draft tube is especially challenging to simulate mainly due to flow phenomena, like swirl, separation and strong adverse pressure gradients, and a strong dependency on the upstream flow conditions. Standard simulation approaches with RANS turbulence models, a coarse mesh and large time step size often fail to correctly predict performance and can even lead to wrong tendencies in the overall behavior. To reveal occurring flow phenomena and physical effects, a scale-resolving hybrid RANS-LES simulation on a block structured mesh of about 400 million hexahedral elements of a double-regulated five-blade model Kaplan turbine is carried out. In this paper, first, the results of the ongoing simulation are presented. The major part of the simulation domain is running in LES mode and seems to be properly resolved. The validation of the simulation results with the experimental data shows mean deviations of less than 0.8% in the global results, i.e., total head and power, and a good visual agreement with the three-dimensional PIV measurements of the velocity in the cone and both diffuser channels of the draft tube. In particular, the trend of total head and the results for the draft tube differ significantly between the scale-resolving simulation and a standard RANS simulation. The standard RANS simulation exhibits a highly unsteady behavior of flow, which is not observed in the experiments or scale-resolving simulation.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-08-02
      DOI: 10.3390/ijtpp8030026
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 27: Effect of the von Karman Shedding Frequency on
           the Hydrodynamics of a Francis Turbine Operating at Nominal Load

    • Authors: Giacomo Zanetti, Giovanna Cavazzini, Alberto Santolin
      First page: 27
      Abstract: This paper presents a numerical analysis of the influence of the von Karman vortex shedding at the blade trailing edge on the hydrodynamics of a recently installed small hydro Francis turbine manifesting very loud and high-frequency acoustic pulsations when operating close to the nominal load. A reduced single-passage numerical model is developed to reduce the computational effort of the simulation while ensuring high accuracy in the assessment of fluid flow. The accuracy of the proposed numerical approach is investigated by comparing the frequency spectrum of the experimentally acquired acoustic frequency and the numerical pressure signals, confirming the nature of the machine’s vibrations. The validated numerical model represents a useful tool for an in-depth analysis of the machine’s hydrodynamics in the preliminary design phases. The proposed approach represents a valid alternative to the traditional correlation-based approach for the evaluation of the von Karman shedding frequency with less computational effort compared with a transient simulation of the entire machine.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-08-07
      DOI: 10.3390/ijtpp8030027
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 28: Three-Dimensional Flow Simulation by a Hybrid
           Two-Phase Solver for the Assessment of Liquid/Gas Transport in a
           Volute-Type Centrifugal Pump with Twisted Blades

    • Authors: Markus Hundshagen, Kevin Rave, Michael Mansour, Dominique Thévenin, Romuald Skoda
      First page: 28
      Abstract: A hybrid two-phase flow solver is proposed, based on an Euler–Euler two-fluid model with continuous blending of a Volume-of-Fluid method when phase interfaces of coherent gas pockets are to be resolved. In a preceding study on a two-dimensional bladed research pump with reduced rotational speed, the transition from bubbly flow to coherent steady gas pockets observed in optical experiments with liquid/gas flow could be well captured by the hybrid solver. In the present study, the experiments and solver validation are extended to an industrial-scale centrifugal pump with twisted three-dimensional blades and elevated design rotational speed. The solver is combined with a population balance model, and a scale-adaptive turbulence model is employed. Compared to the two-dimensional bladed pump, the transition from agglomerated bubbles flow to attached gas pockets is shifted to larger gas loading, which is well captured by the simulation. The pump head drop with increasing gas load is also reproduced, showing the hybrid solver’s validity for realistic pump operation conditions.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-08-30
      DOI: 10.3390/ijtpp8030028
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 29: Suitability of a Profile with Tubercles for Axial
           Pumps—Investigation Using Flow Simulation

    • Authors: Mareen Derda, Ferdinand Neumann, Paul Uwe Thamsen
      First page: 29
      Abstract: Even if wind tunnel tests and simulations have confirmed that tubercles can influence the behaviour of a profile, research in the field of axial pumps has so far been lacking. However, previous studies cannot be transferred to the application of axial pumps, since the requirements for the profile geometry as well as the Reynolds number range differ. The present study aims to address this research gap by performing a CFD simulation with a profile common for axial pumps, the Goe11K, testing four different tubercle configurations. At the same time, this simulation is a preliminary study for experimental tests. The results show that certain tubercle configurations improve the behaviour of the profile in the post-stall area, i.e., increase the lift of the profile at large angles of attack (α). In general, the curve of the profiles with tubercles runs more evenly, without the drastic drop in lift. This improved property comes at the expense of lower maximum lift and increased drag at lower α. With regard to the use of axial pumps, it can be concluded that there are advantages, particularly in the partial load range. These could ultimately enlarge the operation range of an axial pump.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-01
      DOI: 10.3390/ijtpp8030029
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 30: Effect of Tip Gap Size on the Performance of an
           Axial Compressor Stage with and without Active Flow Control

    • Authors: Clémence Rannou, Julien Marty, Geoffrey Tanguy, Antoine Dazin
      First page: 30
      Abstract: The tip gap region of an axial compressor rotor is a source of complex flows, inducing losses and stability issues. Recent works have proven the ability of blowing high-speed jets in the tip region to improve the surge margin of an axial compressor stage with a narrow tip gap configuration. However, the tip gap size can evolve during the compressor lifetime, possibly affecting its performance and operability. The objective is to evaluate the performance of an active flow control system on a compressor with different tip gap sizes. The present work is based on the single-stage compressor CME2 located at the Laboratory of Fluid Mechanics of Lille and equipped with actuators blowing at the rotor tip leading edge. Configurations with two different values of the tip gap to chord ratio (0.6% and 2.4%) are experimentally tested. RANS simulations are also performed. The effect of tip gap sizes and tip blowing on the flow topology and compressor performance is evaluated (surge margin improvement of the order of 200% for the larger tip gap size).
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-01
      DOI: 10.3390/ijtpp8030030
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 31: Experimental Validation of a Numerical Coupling
           Environment Applying FEM and CFD

    • Authors: Christopher Hartmann, Julia Schweikert, François Cottier, Ute Israel, Jochen Gier, Jens von Wolfersdorf
      First page: 31
      Abstract: Experimental results for the transient heat transfer characteristics over a flat plate and over a plate with V-shaped ribs were compared to numerical results from a coupling environment applying FEM and CFD. In order to simulate transient effects in the cooling process of engine components during typical flight missions, the temperature and the velocity at the inlet of the channel were varied over time. The transient temperature distribution at the plate was measured using infrared thermography. Five different plate materials (perspex, PEEK, quartz, aluminum, and steel) were considered to investigate the influence of thermal conduction on the heat transfer between solid and fluid depending on the Biot number. The experimental results represent a reference database for a Python-based coupling environment applying CalculiX (FEM) and ANSYS CFX (CFD). The results were additionally compared to numerical results simulating the complete transient conjugated heat transfer with CFD. A good agreement between the numerical and the experimental results was achieved using different coupling sizes at different Biot numbers for the flat plate and the plate with V-shaped ribs.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-04
      DOI: 10.3390/ijtpp8030031
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 32: Acoustic Boundary Conditions for Can-Annular
           Combustors

    • Authors: James Brind
      First page: 32
      Abstract: This paper derives and validates an analytical model for acoustic boundary conditions on a can-annular gas turbine combustion system composed of discrete cans connected to an open annulus upstream of a turbine. The analytical model takes one empirical parameter: a connection impedance between adjacent cans. This impedance is extracted from time-marching computations of two-can sectors of representative combustors. The computations show that reactance follows the Rayleigh conductivity, while resistance takes a value of order 0.1 as a weak function of geometry. With a calibrated value of acoustic resistance, the analytical model reproduces can-to-can transfer functions predicted by full-annulus computations to within 0.03 magnitude at compact frequencies. Varying the combustor–turbine gap length, both model and computations exhibit a minimum in reflected energy, which drops by 63% compared to the datum gap. A parametric study yields a design guideline for gap length at the minimum reflected energy, allowing the designer to maximise transmission from the combustion system and reduce damping requirements.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-08
      DOI: 10.3390/ijtpp8030032
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 33: Potential of Static Pressure Recovery of
           Rotor-Only Low-Pressure Axial Fans

    • Authors: Hauke Witte, Christoph Bode, Jens Friedrichs
      First page: 33
      Abstract: Typically installed in a rotor-only configuration, low-pressure axial fans discharge directly into a free atmosphere and the discharge shows a strong swirl component. Since such designs, without guide vanes, cannot convert the dynamic pressure in the swirl component back into static pressure, the dynamic pressure is usually considered a loss. However, the radial equilibrium shows that a significant part of the kinetic energy contained in this swirl component is recovered as static pressure in the free atmosphere. This additional pressure increase has been sparsely researched. A comparison between two configurations with and without outlet guide vanes allows for the formulation of an evaluation criterion of the rotor-only configuration. Utilizing this evaluation criterion, the investigation of velocity profiles corresponding to generic rotor designs shows promise in terms of pressure recovery for new designs.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-08
      DOI: 10.3390/ijtpp8030033
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 34: Characterization of Unsteady Leakage Flow in an
           Axial Fan

    • Authors: Matteo Dellacasagrande, Edward Canepa, Andrea Cattanei, Mehrdad Moradi
      First page: 34
      Abstract: The present work reports an experimental study of the leakage flow in a low-speed fan ring. Existing 2D Particle Image Velocimetry (PIV) measurements taken in a meridional plane in front of the rotor gap have been further processed and analyzed by means of the Proper Orthogonal Decomposition (POD). Three values of the dimensionless pressure rise across the rotor have been investigated. Namely, attention has been focused on the intermediate case—the one for which a strong radial oscillation in the leakage flow has been observed: POD results have shown that, in this condition, the leakage flow exhibits periodic radial oscillations that are not correlated to the periodic blade passing. Moreover, such coherent motions have been found to promote turbulence transport at different radial positions, whereas rotor-related oscillations have a negligible effect in this sense. The present POD procedure can be generally applied to turbomachinery flows to characterize their unsteady behavior beside the classical phase-averaging methods based on rotor-related quantities. The present approach is novel for the study of leakage flow dynamics in axial fans.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-13
      DOI: 10.3390/ijtpp8030034
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 35: Effects of Periodic Incoming Wakes on the
           Aerodynamics of a High-Speed Low-Pressure Turbine Cascade

    • Authors: Loris Simonassi, Gustavo Lopes, Sergio Lavagnoli
      First page: 35
      Abstract: The influence of unsteady wakes incoming from the upstream stages is of high relevance in modern high-speed, low-pressure turbines (LPT) operating at transonic exit Mach numbers and low Reynolds numbers for their potential to trigger transition and influence the separation of the boundary layer on the blade suction side. The aim of this paper is the experimental characterization of the influence of incoming wakes on the 2D aerodynamics of a high-speed LPT cascade operating at a low Reynolds number and transonic exit Mach number. A detailed analysis of the status of the flow along the blade under investigation and its impact on the profile loss are presented for a range of Mach numbers from 0.70 to 0.95 and Reynolds numbers from 70k to 120k under steady and unsteady inflow conditions. Tests were conducted at on- and off-design engine realistic conditions in the VKI S-1/C wind tunnel on the SPLEEN C1 transonic cascade. The wakes incoming from an upstream blade row have been replicated using a set of rotating bars, which shed wakes at an engine-representative reduced frequency (f+=0.95) and flow coefficient (Φ=0.80). A set of densely instrumented traversable blades were used to sample the surface pressure distributions. The development of the boundary layers along the blade suction side is examined through quasi-wall shear stress obtained with surface-mounted hot-film sensors. Wake traverses were carried out downstream of the cascade with a miniaturized L-shaped five-hole probe to characterize the blade losses. The introduction of periodic incoming wakes promotes variations in the flow topology over the blade. The effect on the suction side separation bubble is shown to depend on the exit flow conditions. At low Mach numbers, the incoming wakes determine a reduction in the size of the bubble; in contrast, this effect is not registered as the exit Mach number increases. Consistently, a high dependence of the unsteady wake effect on the profile loss on the exit Reynolds and Mach numbers is demonstrated.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-09-13
      DOI: 10.3390/ijtpp8030035
      Issue No: Vol. 8, No. 3 (2023)
       
  • IJTPP, Vol. 8, Pages 11: Experimental Investigation Techniques for
           Non-Ideal Compressible Fluid Dynamics

    • Authors: Stefan aus der Wiesche
      First page: 11
      Abstract: The rising number of applications of the organic Rankine cycle (ORC) or supercritical CO2 (sCO2) power systems have shaped a new branch of fluid mechanics called non-ideal compressible fluid dynamics (NICFD). This field of fluid mechanics is concerned with flows of vapors or gases, which are characterized by substantial deviations from the perfect gas model. In extreme cases, even non-classical gas dynamic phenomena could occur. Although these non-ideal compressible flows are the subject of sophisticated numerical simulation studies today, there is also a growing need for experimental data for validating purposes. In the last couple of years, new experimental test rigs designed for investigating non-ideal compressible fluid dynamics have been developed and commissioned. Classical practical measurement techniques are currently being re-developed and applied to non-ideal compressible flows. Despite its substantial relevance, information about these measurement techniques and their differences from conventional methods in the open literature is scarce. The present review article is an attempt to reduce that gap. After briefly discussing the thermodynamics and fluid dynamics of non-ideal compressible flows, the currently available test rigs and their utilized measurement techniques are reviewed. This review discusses schlieren optical investigations, pneumatic and laser-optical methods, and hot-wire anemometry for non-ideal compressible flows.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-04-03
      DOI: 10.3390/ijtpp8020011
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 12: Optimization, Control, and Design of Arbitrarily
           Shaped Fan Arrays

    • Authors: Daniel Conrad, Jonathan Mayer, Erik Reichert
      First page: 12
      Abstract: In many air conditioning applications fan arrays offer an increasingly popular alternative to single large fans due to redundancy and ease of maintainability. Additionally, there is the possibility to dynamically resize the array by selectively turning off a number of fans. In this work, a new method for the optimal control of such fan arrays is derived with the goal to minimize the overall power consumption, i.e., maximizing the system efficiency. The approach is universal in the sense that a fan array can be composed of any number, size, and type of fans or mixtures thereof. We explore the achievable power savings for a real world example by applying the method. Moreover, we give an outline of the optimal design of fan arrays and future work.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-04-06
      DOI: 10.3390/ijtpp8020012
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 13: Aeroacoustic Simulations of an Axial Fan with
           Modelled Turbulent Inflow Conditions

    • Authors: Philipp Dietrich, Marc Schneider
      First page: 13
      Abstract: In applications, the acoustics of fans can differ significantly from the measurements of the standalone fan. This is due to disturbed inflow conditions, for example, caused by a heat exchanger upstream of an axial fan. Resolving the complex geometry and dimensions of typical heat exchangers in aeroacoustic scale-resolving simulations leads to a very high computation effort, which is currently not economically feasible. Turbulence reconstruction tools, such as the FRPM, provide the possibility to model the turbulent inflow conditions, thereby avoiding the representation of the heat exchanger in the aeroacoustic simulations. This approach is tested on a benchmark experiment of a ducted fan with an upstream turbulence grid.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-04-18
      DOI: 10.3390/ijtpp8020013
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 14: Numerical Analysis of the Flow by Using a Free
           Runner Downstream the Francis Turbine

    • Authors: Alin Ilie Bosioc, Raul-Alexandru Szakal, Adrian Stuparu, Romeo Susan-Resiga
      First page: 14
      Abstract: The current requirements of industrialized countries require the use of as much renewable energy as possible. One significant problem with renewable energy is that the produced power fluctuates. Currently, the only method available for energy compensation in the shortest time is given by hydroelectric power plants. Instead, hydroelectric power plants (especially the plants equipped with hydraulic turbines with fixed blades) are designed to operate in the vicinity of the optimal operating point with a maximum ±10% deviation. The energy market requires that hydraulic turbines operate in an increasingly wide area between −35% to 20% from the optimum operating point. Operation of hydraulic turbines far from the optimum operating point involves the appearance downstream of the turbine of a decelerated swirling flow with hydraulic instabilities (known in the literature as the vortex rope). The main purpose of this paper is to investigate numerically a new concept by using a free runner downstream on the main hydraulic runner turbine more precisely in the draft tube cone. The free runner concept requires rotations at the runaway speed with vanishing mechanical torque. The main purpose is to redistribute the total pressure and the moment between the shaft and the periphery. In addition, the free runner does not modify the operating point of the main hydraulic turbine runner.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-05-04
      DOI: 10.3390/ijtpp8020014
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 15: State of the Art on Two-Phase Non-Miscible
           Liquid/Gas Flow Transport Analysis in Radial Centrifugal Pumps Part C: CFD
           Approaches with Emphasis on Improved Models

    • Authors: Markus Hundshagen, Romuald Skoda
      First page: 15
      Abstract: Predicting pump performance and ensuring operational reliability under two-phase conditions is a major goal of three-dimensional (3D) computational fluid dynamics (CFD) analysis of liquid/gas radial centrifugal pump flows. Hence, 3D CFD methods are increasingly applied to such flows in academia and industry. The CFD analysis of liquid/gas pump flows demands careful selection of sub-models from several fields in CFD, such as two-phase and turbulence modeling, as well as high-quality meshing of complex geometries. This paper presents an overview of current CFD simulation strategies, and recent progress in two-phase modeling is outlined. Particular focus is given to different approaches for dispersed bubbly flow and coherent gas accumulations. For dispersed bubbly flow regions, Euler–Euler Two-Fluid models are discussed, including population balance and bubble interaction models. For coherent gas pocket flow, essentially interface-capturing Volume-of-Fluid methods are applied. A hybrid model is suggested, i.e., a combination of an Euler–Euler Two-Fluid model with interface-capturing properties, predicting bubbly flow regimes as well as regimes with coherent gas pockets. The importance of considering scale-resolving turbulence models for highly-unsteady two-phase flow regions is emphasized.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-05-04
      DOI: 10.3390/ijtpp8020015
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 16: State of the Art on Two-Phase Non-Miscible
           Liquid/Gas Flow Transport Analysis in Radial Centrifugal Pumps-Part A:
           

    • Authors: Gerard Bois
      First page: 16
      Abstract: Gas–liquid mixtures are present in numerous industrial applications, such as in the process industry, oil production and transport with natural gas, deep-sea extraction, and irrigation. Any pump may have to carry multiphase flows. However, the present document is related to non-miscible liquid/gas flow transport analysis in centrifugal pumps because which topic can be a more challenging task compared with axial and mixed flow machines due to specific body force and buoyancy actions and large density differences between the phases. The present document first introduces the main usual gas–liquid two-phase definitions and simplifications. A dimensional analysis introduces the main flow variables and parameters that are used for pumps. Basic physical aspects of flow motion in an impeller channel are explained, and a rapid description of two-phase flow patterns in radial flow pumps is described. Finally, a review of simplified empirical and semi-empirical analytical models is proposed with their limitations.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-05-10
      DOI: 10.3390/ijtpp8020016
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 17: Effects of Tip Leakage Vortex Cavitation on Flow
           Field under Cavitation Instability

    • Authors: Youngkuk Yoon, Seung Jin Song
      First page: 17
      Abstract: Cavitation instabilities can induce axial and circumferential vibrations, as well as noise in turbopump inducers. Therefore, the purpose of the present study is to investigate the mechanism of cavitation instability. The flow field near the two-bladed inducer leading edge under alternate blade cavitation was experimentally investigated using particle image velocimetry (PIV). It was found that the tip leakage vortex cavitation draws the flow toward its region of collapse and induces a negative change in the incidence to the adjacent blade. Moreover, this blade-to-blade interaction was identified as the main cause of alternate blade cavitation. Furthermore, it was demonstrated that this blade-to-blade interaction is strongest when the cavity collapse occurs in the inducer throat area, where the leading edge of the following blade is located.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-06-01
      DOI: 10.3390/ijtpp8020017
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 18: Development of Sewage Pumps with Numerical and
           Experimental Support

    • Authors: David Beck, Paul Uwe Thamsen
      First page: 18
      Abstract: Especially in the field of sewage pumps, the design of radial impellers focuses not only on maximum efficiency but also on functionality in terms of susceptibility to clogging by fibrous media. In general, the efficiency of sewage impellers is significantly lower than that of clear water impellers. These sewage impellers are designed with a low number of blades to ensure that fibrous media can be pumped. This paper describes the methodology of an optimisation for a sewage impeller. The optimisation is carried out on a semi-open two-channel impeller as an example. Therefore, a new impeller is designed for a given volute casing. Based on a basic design for given boundary conditions, the impeller is verified by means of numerical simulation. The manufactured impeller is then tested on the test rig to verify the simulation. With regard to the optical investigations, the clogging behaviour of the impeller is specifically improved over three different modifications in order to finally present an impeller with good efficiency and a low clogging tendency.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-06-02
      DOI: 10.3390/ijtpp8020018
      Issue No: Vol. 8, No. 2 (2023)
       
  • IJTPP, Vol. 8, Pages 1: Active Turbulence Grid-Controlled Inflow
           Turbulence and Replication of Heat Exchanger Flow Fields in Fan
           Applications

    • Authors: Felix Czwielong, Stefan Becker
      First page: 1
      Abstract: A novel active turbulence grid of the Institute of Fluid Mechanics at FAU Erlangen-Nuremberg is introduced. The focus of this grid is not on basic investigations of fluid mechanics, as is usually the case with active turbulence grids, but the generation of defined inflow conditions for axial fans. Thus, by means of the active turbulence grid, individual turbulence characteristics in the flow to the fan can be changed; therefore, fundamental interactions between the flow mechanics at the axial fan and the sound radiation can be analyzed. In addition, the replication of the flow fields of heat exchangers by the active turbulence grid is the focus of the investigations. The investigations showed that it is possible to use the active turbulence grid to generate defined inflow conditions for axial fans. It was also possible to reproduce the heat exchanger flow fields both for the mean turbulence values and for the spatial distributions. It was found that the grid induces tonal components due to the drive motors, but also that the inherent noise has no significant influence on the spectrum of the fans under investigation. Based on selected turbulence characteristics, direct correlations were found between the spatial distribution of the turbulence level and sound radiation at the first blade passing frequency of the axial fan. As the variance of the turbulence level increases, the sound radiation of the tonal components becomes more pronounced. The total sound pressure level, however, is mainly determined by the low-frequency broadband sound. A linear relationship between the spatial mean value of the turbulence level and the total sound pressure level was found for the investigated axial fan.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-01-04
      DOI: 10.3390/ijtpp8010001
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 2: Acknowledgment to the Reviewers of IJTPP in 2022

    • Authors: IJTPP Editorial Office IJTPP Editorial Office
      First page: 2
      Abstract: High-quality academic publishing is built on rigorous peer review [...]
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-01-20
      DOI: 10.3390/ijtpp8010002
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 3: Data-Driven Anomaly Detection Framework for
           Complex Degradation Monitoring of Aero-Engine

    • Authors: Zichen Yan, Jianzhong Sun, Yang Yi, Caiqiong Yang, Jingbo Sun
      First page: 3
      Abstract: Data analysis is an important part of aero engine health management. In order to complete accurate condition monitoring, it is necessary to establish more effective analysis tools. Therefore, an integrated algorithm library dedicated for engine anomaly detection is established, which is PyPEFD (Python Package for Engine Fault Detection). Different algorithms for baseline modeling, anomaly detection and trend analysis are presented and compared. In this paper, the simulation data are used to verify the function of the anomaly detection algorithms, successfully completing the detection of multiple faults and comparing the accuracy algorithm under different conditions.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-02-01
      DOI: 10.3390/ijtpp8010003
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 4: Exergy-Based Efficiency Assessment of Fans vs.
           Isentropic Efficiency

    • Authors: Johannes Brötz, Christian Schänzle, Peter F. Pelz
      First page: 4
      Abstract: The efficiency definition allows us to compare two machines with each other. In general, the efficiency is defined as the ratio of usable power to the required power. This raises the question: what is the usable power' Most engineers discuss efficiency on the basis of the energy balance, i.e., the first law of thermodynamics. In this paper, we derive the exegetic efficiency taking the second law of thermodynamics into account. Exergy analysis takes into account work and heat and is able to model reality very accurately. On this basis, a comparison between the isentropic and exergetic efficiencies is given. A high-pressure radial fan is used as an example, and the differences are discussed. Therefore, measurements of a non-adiabatic fan are evaluated, and the role of the heat flux in the environment is discussed. The investigations show that a relevant difference between the isentropic and exergetic efficiencies becomes apparent in the partial-load range with high-pressure build-up. The thermal energy contained in the flow belongs proportionally to the exergy, i.e., the working capacity of the gas relative to its environment. For a standard such as ISO 5801 “Fans—Performance testing using standardized airways”, the efficiency must not only be physically correct, it must also be simple and practical. Against this background, the outlook of this paper discusses when and which efficiency definition is appropriate and best suited for a standard.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-02-06
      DOI: 10.3390/ijtpp8010004
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 5: Numerical Determination of the Equivalent Sand
           Roughness of a Turbopump’s Surface and Its Roughness Influence on
           the Pump Characteristics

    • Authors: Benjamin Torner, Duc Viet Duong, Frank-Hendrik Wurm
      First page: 5
      Abstract: The correct computation of flows over rough surfaces in technical systems, such as in turbomachines, is a significant issue for proper simulations of their performance data. Once the flow over rough surfaces is adequately computed in these machines, simulations become more trustworthy and can replace experimental prototyping. Roughness modelling approaches are often implemented in a solver to account for roughness effects in flow simulations. In these approaches, the equivalent sand roughness ks must be defined as a characteristic parameter of the rough surface. However, it is difficult to determine the corresponding ks-value for a surface roughness. In this context, this paper shows a novel and time-efficient numerical method, the discrete porosity method (DPM), which can be used to determine the ks-value of a rough surface. Applying this method, channel flow simulations were performed with an irregularly distributed cast iron surface from a turbopumps volute. After identifying the fully rough regime, the equivalent sand roughness was determined and a match with ks-values from literature data was found. Subsequently, the established ks-value for cast iron was used in a turbopump simulation with rough walls. The performance data of the pump were validated by experiments and a good agreement between the experimental and simulated performance data was found.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-02-07
      DOI: 10.3390/ijtpp8010005
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 6: Enhancement of Rotor Loading and Suppression of
           Stator Separation through Reduction of the Blade–Row Gap

    • Authors: Wang, Du, Sun
      First page: 6
      Abstract: An immersed boundary (IB) method is applied to study the effect of the blade–row gap in a low-speed single-stage compressor. The advantage of using an IB method is that the rotor/stator interface can be eliminated and, thus, the blade–row interaction can be considered at an extremely small gap. The IB method was modified to internal-flow problems, and the adaptive mesh refinement (AMR) technique, together with a wall model, used to facilitate the simulations for high Reynoldsnumber flows. The results showed that both the pressure rise and the efficiency were observed to be higher in the smaller-gap cases. Comparisons between the results of two gaps, 35%ca and 3.5%ca, are highlighted and further analysis at a specific flow coefficient showed that the increase of the stage performance was contributed to by the enhancement of rotor loading and the suppression to the flow separation of the stator. Correspondingly, the increases of the total pressure rise on the rotor and the stator outlets were observed to be 0.5% and 4.3%, respectively. Although the increase on the rotor outlet is much lower than that on the stator outlet, its significance is that a higher level of static pressure is formed near the hub of the gap, which, thus, reduces the adverse pressure gradient of this region in the stator passage. This improvement suppresses the flow separation near the hub of the stator and, thereby, results in a considerable increase to the pressure rise on the stator outlet as a consequence. The effect of the gap on unsteady pressure fluctuation is also presented.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-03-01
      DOI: 10.3390/ijtpp8010006
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 7: Axial Impeller-Only Fans with Optimal Hub-to-Tip
           Ratio and Blades Adapted for Minimum Exit Loss

    • Authors: Thomas Carolus, Konrad Bamberger
      First page: 7
      Abstract: This study targets determining impellers of impeller-only axial fans with an optimal hub-to-tip ratio for the highest achievable total-to-static efficiency. Differently from other studies, a holistic approach is chosen. Firstly, the complete class of these fans is considered. Secondly, the radial distribution of blade sweep angle, stagger angle, chord length, and camber are varied to adapt the blades to the complex flow in the hub and tip regions. The tool being used is an optimization scheme with three key components: (i) a database created beforehand by Reynolds-averaged Navier–Stokes (RANS)-predicted performance characteristics of 14,000 designs, (ii) an artificial neural network as a metamodel for the fan performance as a function of 26 geometrical parameters, and (iii) an evolutionary algorithm for optimization, performed on the metamodel. Typically, the hub-to-tip ratios for the impellers proposed by the optimization scheme are smaller than those obtained by applying the classic design rules. A second outcome are the shapes of the blades, which are adapted for a minimum exit loss. These shapes deviate substantially from the classic and even the state-of-the-art “swept-only” or “swept with dihedral” designs. The chord length, stagger, and sweep angle are distributed from hub to tip in a complex manner. The inherent reason is that the scheme tries to minimize not only the dynamic exit loss but also frictional losses due to secondary flows in the hub and tip regions, which eventually results in the maximum achievable total-to-static efficiency. Upon request, the authors will provide the full geometry of the four impellers analysed in some detail in this study to any individual for experimental validation or further analysis of their performance.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-03-01
      DOI: 10.3390/ijtpp8010007
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 8: Multi-Point, Multi-Objective Optimisation of
           Centrifugal Fans by 3D Inverse Design Method

    • Authors: Jiangnan Zhang, Mehrdad Zangeneh
      First page: 8
      Abstract: In this paper, we present the design and optimization of a centrifugal fan with requirements of maximizing the total-to-static pressure rise and total-to-static efficiency at two operating points and the maximum torque provided by the motor power using a 3D inverse design method, a DOE (design of experiment) study, an RSM (response surface model) and a MOGA (multi-objective genetic algorithm). The fan geometry is parametrized using 13 design parameters, and 120 different designs are generated. The fan performances of all the designs at two operating conditions are evaluated through steady-state CFD simulations. The resulting design matrix is used to create an RSM based on the Kriging method and MOGA is used to search the design space using the RSM and find the optimal design.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-03-02
      DOI: 10.3390/ijtpp8010008
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 9: Leading Edge Bumps for Flow Control in Air-Cooled
           Condensers

    • Authors: Lorenzo Tieghi, Giovanni Delibra, Johan van der Spuy, Alessandro Corsini
      First page: 9
      Abstract: Air-cooled condensers (ACCs) are commonly found in power plants working with concentrated solar power or in steam power plants operated in regions with limited water availability. In ACCs, the flow of air is driven toward the heat exchangers by axial fans that are characterized by large diameters and operate at very high mass flow rates with a near-zero static pressure rise. Given the overall requirements in steam plants, these fans are subjected to inflow distortions, unstable operations, and are characterized by high noise emissions. Previous studies show that leading edge bumps in the tip region of axial fans can effectively reduce the sound pressure levels without affecting the static efficiency. Nevertheless, the effects of this treatment in terms of flow patterns and heat exchange in the whole ACC system were not investigated. In this work, the effect of leading edge bumps on the flow patterns is analyzed. Two RANS simulations were carried out using OpenFOAM on a simplified model of the air-cooled condenser. The fans are simulated using a frozen rotor approach. Turbulence modeling relies on the RNG k-epsilon model. The fan is characterized by a diameter of 7.3 m and a 333 m3/s volumetric flow rate at the design point. The presence of the heat exchanger is modeled using a porous medium. The comparison between the flow fields clearly exerts that the modified blade is responsible for the redistribution of radial velocities in the rotor region. This drastically reduces the losses related to the installation of the fan in a real configuration.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-03-09
      DOI: 10.3390/ijtpp8010009
      Issue No: Vol. 8, No. 1 (2023)
       
  • IJTPP, Vol. 8, Pages 10: Transient 3D CFD Simulation of a Pelton
           Turbine—A State-of-the-Art Approach for Pelton Development and
           Optimisation

    • Authors: Lukas Sandmaier, Peter Meusburger, Helmut Benigni
      First page: 10
      Abstract: The complex flow conditions in Pelton turbines make it challenging to gain detailed insight into the local flow processes. However, CFD methods offer vast potential for developing and optimising Pelton turbines due to these flow conditions. In a comprehensive examination, a six-nozzle prototype Pelton turbine with 19 buckets has been investigated using 3D CFD simulations. First, the steady simulations of the manifold and the unsteady runner simulation have been performed with a mesh-based, commercial CFD code, whereby a two-equation turbulence model and the homogeneous two-phase model were used. Then, to limit the simulation time, symmetry was applied in the runner simulation, and also a strategic definition of the mesh element size in selected blocks of higher interest. Subsequently, the simulation results were analysed. Based on the first simulation results, the geometry of the distributor was modified in an iterative process to reduce losses and improve the jet shape. For the improvement of the latter, a characteristic number was introduced to quantify the secondary flows upstream of the nozzles, which act negatively on the jet shape. Furthermore, the results of the runner simulation were analysed with special regard to the jet-bucket interaction from the start to the end of the impingement cycle of a particular bucket. Finally, a potential efficiency increase could be derived from the summary.
      Citation: International Journal of Turbomachinery, Propulsion and Power
      PubDate: 2023-03-09
      DOI: 10.3390/ijtpp8010010
      Issue No: Vol. 8, No. 1 (2023)
       
 
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  Subjects -> ENERGY (Total: 414 journals)
    - ELECTRICAL ENERGY (12 journals)
    - ENERGY (252 journals)
    - ENERGY: GENERAL (7 journals)
    - NUCLEAR ENERGY (40 journals)
    - PETROLEUM AND GAS (58 journals)
    - RENEWABLE ENERGY (45 journals)

ENERGY (252 journals)                  1 2 | Last

Showing 1 - 200 of 406 Journals sorted by number of followers
Energy Policy     Partially Free   (Followers: 77)
IET Power Electronics     Open Access   (Followers: 69)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 55)
IEEE Transactions on Power Systems     Hybrid Journal   (Followers: 48)
Energy     Partially Free   (Followers: 41)
Journal of Physical Chemistry C     Hybrid Journal   (Followers: 37)
Nature Energy     Hybrid Journal   (Followers: 37)
International Journal of Hydrogen Energy     Partially Free   (Followers: 35)
IEEE Power and Energy     Full-text available via subscription   (Followers: 34)
Applied Energy     Partially Free   (Followers: 32)
Energy & Fuels     Hybrid Journal   (Followers: 29)
Solar Energy Materials and Solar Cells     Hybrid Journal   (Followers: 29)
Advances in High Energy Physics     Open Access   (Followers: 26)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 26)
Energy & Environment     Hybrid Journal   (Followers: 25)
Energy and Power Engineering     Open Access   (Followers: 23)
International Journal of Turbomachinery, Propulsion and Power     Open Access   (Followers: 22)
Applied Solar Energy     Hybrid Journal   (Followers: 21)
International Journal of Alternative Propulsion     Hybrid Journal   (Followers: 21)
Solar Energy     Hybrid Journal   (Followers: 20)
Energy Materials : Materials Science and Engineering for Energy Systems     Hybrid Journal   (Followers: 19)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 19)
Water International     Hybrid Journal   (Followers: 19)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 18)
Energy and Power     Open Access   (Followers: 18)
IEEE Transactions on Energy Conversion     Hybrid Journal   (Followers: 16)
Nuclear Engineering and Design     Hybrid Journal   (Followers: 16)
Energy, Sustainability and Society     Open Access   (Followers: 16)
Economics and Policy of Energy and the Environment     Full-text available via subscription   (Followers: 16)
Energy Conversion and Management     Hybrid Journal   (Followers: 15)
Progress in Energy and Combustion Science     Hybrid Journal   (Followers: 14)
Waste Management     Hybrid Journal   (Followers: 14)
Energy and Environment Research     Open Access   (Followers: 14)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 14)
Advances in Energy and Power     Open Access   (Followers: 14)
Surface Science Reports     Full-text available via subscription   (Followers: 13)
Annual Review of Resource Economics     Full-text available via subscription   (Followers: 13)
Energy Journal The     Hybrid Journal   (Followers: 13)
Energy Research & Social Science     Full-text available via subscription   (Followers: 13)
Energy and Buildings     Hybrid Journal   (Followers: 12)
International Journal of Sustainable Energy     Hybrid Journal   (Followers: 12)
Oil and Gas Journal     Full-text available via subscription   (Followers: 12)
Biofuels     Hybrid Journal   (Followers: 12)
Journal of Solar Energy     Open Access   (Followers: 12)
Journal of Renewable Energy     Open Access   (Followers: 12)
Advances in Building Energy Research     Hybrid Journal   (Followers: 11)
Energy Systems     Hybrid Journal   (Followers: 11)
International Journal of Thermodynamics     Open Access   (Followers: 11)
Joule     Hybrid Journal   (Followers: 11)
IEEE Transactions on Nuclear Science     Hybrid Journal   (Followers: 10)
Innovations : Technology, Governance, Globalization     Hybrid Journal   (Followers: 10)
International Journal of Energy Research     Hybrid Journal   (Followers: 10)
Energy Efficiency     Hybrid Journal   (Followers: 10)
Journal of Ocean and Climate     Open Access   (Followers: 10)
Energy Science and Technology     Open Access   (Followers: 10)
Energy Strategy Reviews     Open Access   (Followers: 10)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Batteries     Open Access   (Followers: 10)
ACS Energy Letters     Hybrid Journal   (Followers: 10)
Archives of Thermodynamics     Open Access   (Followers: 9)
Journal of Modern Power Systems and Clean Energy     Open Access   (Followers: 9)
International Journal of Global Energy Issues     Hybrid Journal   (Followers: 8)
International Journal of Green Energy     Hybrid Journal   (Followers: 8)
Smart Grid and Renewable Energy     Open Access   (Followers: 8)
Wiley Interdisciplinary Reviews : Energy and Environment     Hybrid Journal   (Followers: 8)
International Journal of Energy and Power     Open Access   (Followers: 8)
American Journal of Energy Research     Open Access   (Followers: 8)
CERN courier. International journal of high energy physics     Free   (Followers: 8)
Energy and Environment Focus     Free   (Followers: 8)
Annals of Nuclear Energy     Hybrid Journal   (Followers: 7)
Fuel and Energy Abstracts     Full-text available via subscription   (Followers: 7)
International Journal of Electric and Hybrid Vehicles     Hybrid Journal   (Followers: 7)
Applied Nanoscience     Open Access   (Followers: 7)
Environmental Progress & Sustainable Energy     Hybrid Journal   (Followers: 7)
Energy Storage Materials     Full-text available via subscription   (Followers: 7)
ACS Applied Energy Materials     Hybrid Journal   (Followers: 7)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 6)
Energy Prices and Taxes     Full-text available via subscription   (Followers: 6)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Computational Water, Energy, and Environmental Engineering     Open Access   (Followers: 6)
Materials for Renewable and Sustainable Energy     Open Access   (Followers: 6)
Energy Science & Engineering     Open Access   (Followers: 6)
American Journal of Energy and Environment     Open Access   (Followers: 6)
Atomic Energy     Hybrid Journal   (Followers: 5)
Carbon Management     Open Access   (Followers: 5)
Journal of Energy Technologies and Policy     Open Access   (Followers: 5)
Energy Studies Review     Open Access   (Followers: 5)
Energy Technology     Partially Free   (Followers: 5)
Geothermal Energy     Open Access   (Followers: 5)
Frontiers in Energy Research     Open Access   (Followers: 5)
Journal of Energy, Environment & Carbon Credits     Full-text available via subscription   (Followers: 5)
International Journal of Sustainable Energy Planning and Management     Open Access   (Followers: 5)
Energy and Environmental Engineering     Open Access   (Followers: 5)
Energy Reports     Open Access   (Followers: 5)
Journal of Energy & Natural Resources Law     Hybrid Journal   (Followers: 5)
Annual Reports on NMR Spectroscopy     Full-text available via subscription   (Followers: 4)
Frontiers in Energy     Hybrid Journal   (Followers: 4)
International Journal of Nuclear Energy Science and Technology     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology B: Biology     Hybrid Journal   (Followers: 4)
Wind Energy     Hybrid Journal   (Followers: 4)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 4)
Dams and Reservoirs     Hybrid Journal   (Followers: 4)
Journal of Nano Energy and Power Research     Full-text available via subscription   (Followers: 4)
International Journal of Energy and Environmental Engineering     Open Access   (Followers: 4)
Science and Technology for Energy Transition     Open Access   (Followers: 4)
International Journal of Applied Power Engineering     Open Access   (Followers: 4)
Development of Energy Science     Open Access   (Followers: 4)
Journal of International Energy Policy     Open Access   (Followers: 4)
Foundations and Trends® in Renewable Energy     Full-text available via subscription   (Followers: 4)
International Journal of Energy and Statistics     Hybrid Journal   (Followers: 4)
Sustainable Energy, Grids and Networks     Hybrid Journal   (Followers: 4)
Journal of Energy Chemistry     Full-text available via subscription   (Followers: 4)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Energy, Mechanical, Material and Manufacturing Engineering     Open Access   (Followers: 4)
Journal of Fusion Energy     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 3)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Global Energy Law and Sustainability     Hybrid Journal   (Followers: 3)
Science and Technology of Nuclear Installations     Open Access   (Followers: 3)
Power Technology and Engineering     Hybrid Journal   (Followers: 3)
Functional Materials Letters     Hybrid Journal   (Followers: 3)
Distributed Generation & Alternative Energy Journal     Hybrid Journal   (Followers: 3)
Sustainable Energy     Open Access   (Followers: 3)
Journal of Technology Innovations in Renewable Energy     Hybrid Journal   (Followers: 3)
Journal of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 3)
International Journal of Coal Science & Technology     Open Access   (Followers: 3)
Energy and Emission Control Technologies     Open Access   (Followers: 3)
Asian Bulletin of Energy Economics and Technology     Open Access   (Followers: 3)
Protection and Control of Modern Power Systems     Open Access   (Followers: 3)
Sustainable Energy & Fuels     Hybrid Journal   (Followers: 3)
International Journal of Nuclear Knowledge Management     Hybrid Journal   (Followers: 2)
Progress in Nuclear Energy     Hybrid Journal   (Followers: 2)
Electricity Journal     Hybrid Journal   (Followers: 2)
Proceedings of the Institution of Civil Engineers - Energy     Hybrid Journal   (Followers: 2)
Gcb Bioenergy     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
EPJ Photovoltaics     Open Access   (Followers: 2)
International Journal of Clean Coal and Energy     Open Access   (Followers: 2)
Washington and Lee Journal of Energy, Climate, and the Environment     Open Access   (Followers: 2)
Journal of Energy in Southern Africa     Open Access   (Followers: 2)
Journal of Alternate Energy Sources & Technologies     Full-text available via subscription   (Followers: 2)
Journal of Nuclear Energy Science & Power Generation Technology     Hybrid Journal   (Followers: 2)
Nigerian Journal of Technological Research     Full-text available via subscription   (Followers: 2)
Journal of Energy     Open Access   (Followers: 2)
Energy Technology & Policy     Open Access   (Followers: 2)
Biofuel Research Journal     Open Access   (Followers: 2)
Green Energy & Environment     Open Access   (Followers: 2)
Materials Today Energy     Hybrid Journal   (Followers: 2)
Journal of Power and Energy Engineering     Open Access   (Followers: 2)
Clean Energy     Open Access   (Followers: 2)
Global Challenges     Open Access   (Followers: 2)
Carbon Resources Conversion     Open Access   (Followers: 2)
IET Smart Grid     Open Access   (Followers: 2)
IET Energy Systems Integration     Open Access   (Followers: 2)
International Journal of Nuclear Desalination     Hybrid Journal   (Followers: 1)
International Journal of Nuclear Hydrogen Production and Applications     Hybrid Journal   (Followers: 1)
Radioprotection     Hybrid Journal   (Followers: 1)
Nuclear Law Bulletin     Full-text available via subscription   (Followers: 1)
International Journal of Power and Energy Conversion     Hybrid Journal   (Followers: 1)
Clefs CEA     Full-text available via subscription   (Followers: 1)
Journal of Computational Multiphase Flows     Open Access   (Followers: 1)
Natural Resources     Open Access   (Followers: 1)
Journal of Sustainable Bioenergy Systems     Full-text available via subscription   (Followers: 1)
Open Journal of Energy Efficiency     Open Access   (Followers: 1)
Michigan Journal of Sustainability     Open Access   (Followers: 1)
Technology Audit and Production Reserves     Open Access   (Followers: 1)
Sustainable Energy Technologies and Assessments     Full-text available via subscription   (Followers: 1)
International Journal of Smart Grid and Green Communications     Hybrid Journal   (Followers: 1)
Clean Technologies     Open Access   (Followers: 1)
Energy Conversion and Management : X     Open Access   (Followers: 1)
Technology and Economics of Smart Grids and Sustainable Energy     Hybrid Journal   (Followers: 1)
Energy, Ecology and Environment     Hybrid Journal   (Followers: 1)
International Journal of Energy and Water Resources     Hybrid Journal  
BioPhysical Economics and Resource Quality     Hybrid Journal  
Geomechanics and Geophysics for Geo-Energy and Geo-Resources     Hybrid Journal  
BMC Energy     Open Access  
Journal of Energy and Environment Technology of Graduate School Siam Technology College     Open Access  
Global Energy Interconnection     Open Access  
Journal of Energy Systems     Open Access  
International Journal of Energy & Engineering Sciences     Open Access  
International Journal of Energy and Smart Grid     Open Access  
Turkish Journal of Energy Policy     Open Access  
Energy Informatics     Open Access  
High Voltage     Open Access  
Geomechanics for Energy and the Environment     Full-text available via subscription  
ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations     Open Access  
Journal of China Coal Society     Open Access  
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Universal Journal of Applied Science     Open Access  
Ingeniería Energética     Open Access  
E3S Web of Conferences     Open Access  
International Journal of Ambient Energy     Hybrid Journal  
CT&F - Ciencia, Tecnología y Futuro     Open Access  
Multequina     Open Access  
South Pacific Journal of Natural and Applied Sciences     Hybrid Journal  
Chain Reaction     Full-text available via subscription  
Wind Engineering     Hybrid Journal  
Nuclear Data Sheets     Full-text available via subscription  
International Journal of Nuclear Governance, Economy and Ecology     Hybrid Journal  

        1 2 | Last

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