Nuclear thermal propulsion has the characteristics of high specific impulse, large thrust, green and efficient, and is the primary choice of manned deep space exploration propulsion system. Because the circulating flow of propellant hydrogen in the internal pipeline of the engine is always affected by the harsh environment of high temperature and high pressure, it is very important to study the flow characteristics of hydrogen in the pipeline, the heat exchange characteristics of hydrogen and pipeline and the deformation characteristics of pipeline under heat stress. In this paper, the flow phenomena of hot hydrogen in round tubes in a laminar flow state were analyzed by numerical simulation with COMSOL Mulitiphisics6.0, and the fluid-structure coupling between hot hydrogen fluid and pipe was investigated by a multi-physics field. It is concluded that the smoother the inner wall of the pipeline is, the smaller the hydrogen flow velocity is, the smaller the surface pressure of the pipe wall is, and the smaller the fluid extrusion and impact deformation of the pipe in the typical pipe with the inner fin is. It inspires studying the application of hot hydrogen flow and pipeline configuration in nuclear thermal rocket engines, including improving heat transfer energy and uniformity.
{"title":"Effect of finned configuration of circular tube based on fluid-structure coupling on hydrogen flow characteristics","authors":"Xunliang Wu, Mingxue Shao, Kaiyuan Cai, Xiaoliang Li, Songjiang Feng","doi":"10.1088/1742-6596/2730/1/012058","DOIUrl":"https://doi.org/10.1088/1742-6596/2730/1/012058","url":null,"abstract":"Nuclear thermal propulsion has the characteristics of high specific impulse, large thrust, green and efficient, and is the primary choice of manned deep space exploration propulsion system. Because the circulating flow of propellant hydrogen in the internal pipeline of the engine is always affected by the harsh environment of high temperature and high pressure, it is very important to study the flow characteristics of hydrogen in the pipeline, the heat exchange characteristics of hydrogen and pipeline and the deformation characteristics of pipeline under heat stress. In this paper, the flow phenomena of hot hydrogen in round tubes in a laminar flow state were analyzed by numerical simulation with COMSOL Mulitiphisics6.0, and the fluid-structure coupling between hot hydrogen fluid and pipe was investigated by a multi-physics field. It is concluded that the smoother the inner wall of the pipeline is, the smaller the hydrogen flow velocity is, the smaller the surface pressure of the pipe wall is, and the smaller the fluid extrusion and impact deformation of the pipe in the typical pipe with the inner fin is. It inspires studying the application of hot hydrogen flow and pipeline configuration in nuclear thermal rocket engines, including improving heat transfer energy and uniformity.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141389875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2730/1/012019
Yiyuan Jiang, Li Li, Yujin Hu
Theories of generalized continuum mechanics have found great success in the analysis of nanostructures. However, there exists no work on analysing composites whose constituents are generalized continua. The present work fills this gap and studies the strain gradient viscoelasticity of polymeric nanocomposites. The key problem is to assign the nonclassical boundary condition of the representative volume element (RVE). To resolve it, a perturbation field is superposed on the homogeneous displacement boundary condition. The wavelength of perturbation is comparable to the strain gradient characteristic length. Simulations to obtain the macroscopic effective mechanical properties are performed, which agree well with the experimental data. The frequency dependence of the perturbation field is revealed, and it has a clear physical interpretation in terms of the segmental motions of polymer chains.
{"title":"On modelling strain gradient viscoelasticity of polymer nanocomposites","authors":"Yiyuan Jiang, Li Li, Yujin Hu","doi":"10.1088/1742-6596/2730/1/012019","DOIUrl":"https://doi.org/10.1088/1742-6596/2730/1/012019","url":null,"abstract":"Theories of generalized continuum mechanics have found great success in the analysis of nanostructures. However, there exists no work on analysing composites whose constituents are generalized continua. The present work fills this gap and studies the strain gradient viscoelasticity of polymeric nanocomposites. The key problem is to assign the nonclassical boundary condition of the representative volume element (RVE). To resolve it, a perturbation field is superposed on the homogeneous displacement boundary condition. The wavelength of perturbation is comparable to the strain gradient characteristic length. Simulations to obtain the macroscopic effective mechanical properties are performed, which agree well with the experimental data. The frequency dependence of the perturbation field is revealed, and it has a clear physical interpretation in terms of the segmental motions of polymer chains.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141391315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/6/062025
Deepali Singh, Erik Haugen, K. Laugesen, Ayush Chauhan, A. Viré
Floating offshore wind turbines can extract energy from deep offshore locations, typically unfit for fixed bottom designs. The complex interaction between the structural behavior of the floating offshore wind turbine and the stochastic site conditions, however, is an active area of research. Characterizing the relationship between the environmental conditions and loads may help design reduced-order models, surrogate models, and physics-based engineering models for floating wind turbines. This study uses data from the TetraSpar prototype equipped with a 3.6 MW Siemens Gamesa wind turbine. One-to-one simulations performed using an aero-servo-hydro-elastic software are included for comparison. Various tools, including linear correlation, mutual information, feature ordering using conditional independence, and sensitivity analysis using a data-driven variogram fit, are used for the assessment. This study is also helpful in validating the engineering model for future global sensitivity analysis using elementary effects or Sobol indices that require a rigid sampling of features and can, therefore, only be calculated with simulation tools. We find a good agreement between the experiments and simulations. The 10-min. damage equivalent loads on the tower show a correlation, particularly with the wind speed statistics and the significant wave height.
{"title":"Data analysis of the TetraSpar demonstrator measurements","authors":"Deepali Singh, Erik Haugen, K. Laugesen, Ayush Chauhan, A. Viré","doi":"10.1088/1742-6596/2767/6/062025","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/6/062025","url":null,"abstract":"Floating offshore wind turbines can extract energy from deep offshore locations, typically unfit for fixed bottom designs. The complex interaction between the structural behavior of the floating offshore wind turbine and the stochastic site conditions, however, is an active area of research. Characterizing the relationship between the environmental conditions and loads may help design reduced-order models, surrogate models, and physics-based engineering models for floating wind turbines. This study uses data from the TetraSpar prototype equipped with a 3.6 MW Siemens Gamesa wind turbine. One-to-one simulations performed using an aero-servo-hydro-elastic software are included for comparison. Various tools, including linear correlation, mutual information, feature ordering using conditional independence, and sensitivity analysis using a data-driven variogram fit, are used for the assessment. This study is also helpful in validating the engineering model for future global sensitivity analysis using elementary effects or Sobol indices that require a rigid sampling of features and can, therefore, only be calculated with simulation tools. We find a good agreement between the experiments and simulations. The 10-min. damage equivalent loads on the tower show a correlation, particularly with the wind speed statistics and the significant wave height.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141392355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/3/032009
T. Hovgaard, F. Caponetti, J. D. Grunnet
We present a virtual actuator concept for wind turbine control, wherein rotor force and moment references from various controllers are optimally combined to compute individual blade pitch angles. The approach aims to minimize pitch bearing wear, too. The combined references can come from known control algorithms such as speed regulation, tilt-yaw control, tower dampening and helical wake control [3]. We formulate this as an optimization problem which we solve in an MPC fashion, however, instead of the usual prediction horizon over time, we use a discretized azimuth map as our finite horizon. Serving as a unified interface for all control features utilizing individual pitching, the virtual actuator replaces the plethora of multi-blade transformations and gain-scheduling functions in traditional IPC with one coherent function. Users can directly prioritize features and input constraints on actuators and structural loads. Notably, upstream control algorithms provide rotor force or moment references rather than pitch references. Simulations showcase the virtual actuator’s ability to compute intricate pitch trajectories, surpassing the capabilities of conventional IPC methods. Our method yields novel individual pitching which optimally merges conflicting IPC objectives while minimizing actuator wear.
{"title":"A Virtual Actuator for Advanced Individual Pitch Control (IPC)","authors":"T. Hovgaard, F. Caponetti, J. D. Grunnet","doi":"10.1088/1742-6596/2767/3/032009","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/3/032009","url":null,"abstract":"We present a virtual actuator concept for wind turbine control, wherein rotor force and moment references from various controllers are optimally combined to compute individual blade pitch angles. The approach aims to minimize pitch bearing wear, too. The combined references can come from known control algorithms such as speed regulation, tilt-yaw control, tower dampening and helical wake control [3]. We formulate this as an optimization problem which we solve in an MPC fashion, however, instead of the usual prediction horizon over time, we use a discretized azimuth map as our finite horizon. Serving as a unified interface for all control features utilizing individual pitching, the virtual actuator replaces the plethora of multi-blade transformations and gain-scheduling functions in traditional IPC with one coherent function. Users can directly prioritize features and input constraints on actuators and structural loads. Notably, upstream control algorithms provide rotor force or moment references rather than pitch references. Simulations showcase the virtual actuator’s ability to compute intricate pitch trajectories, surpassing the capabilities of conventional IPC methods. Our method yields novel individual pitching which optimally merges conflicting IPC objectives while minimizing actuator wear.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141393199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/7/072015
H. Zhu, C. Hu, S. Yoshida
The integration of floating offshore wind turbines with wave energy converters is regarded as a promising solution for offshore renewable energy development. Given the early stage of wave energy conversion technologies and the substantial influence of control methods on overall system dynamics, a faithful aero-hydro-thermo-elastic-servo-mooring coupled model, along with an engineering environment offering high flexibility for control implementations, is essential. To address the requirement, a numerical modeling framework is developed in this study based on Simulink, known for its superiority in control design and implementation, and OpenFAST, which offers a reliable floating wind turbine model. The model incorporates the thermodynamics of the air in chambers, power take-off dynamics, and oscillating water column dynamics. Furthermore, bypass valves are utilized for the wave energy converters to adjust chamber pressure and reduce floater motion, with a control law proposed to regulate the valve opening ratio. A case study is conducted under harsh ocean conditions to validate the model. The numerical results not only demonstrate the feasibility of the model but also underscore the effectiveness of the control law in improving floater motion performance.
{"title":"Modelling of a Floating-Type Hybrid Wind-Wave System with Oscillating Water Column Wave Energy Converters: A Study Towards Floater Motion Reduction","authors":"H. Zhu, C. Hu, S. Yoshida","doi":"10.1088/1742-6596/2767/7/072015","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/7/072015","url":null,"abstract":"The integration of floating offshore wind turbines with wave energy converters is regarded as a promising solution for offshore renewable energy development. Given the early stage of wave energy conversion technologies and the substantial influence of control methods on overall system dynamics, a faithful aero-hydro-thermo-elastic-servo-mooring coupled model, along with an engineering environment offering high flexibility for control implementations, is essential. To address the requirement, a numerical modeling framework is developed in this study based on Simulink, known for its superiority in control design and implementation, and OpenFAST, which offers a reliable floating wind turbine model. The model incorporates the thermodynamics of the air in chambers, power take-off dynamics, and oscillating water column dynamics. Furthermore, bypass valves are utilized for the wave energy converters to adjust chamber pressure and reduce floater motion, with a control law proposed to regulate the valve opening ratio. A case study is conducted under harsh ocean conditions to validate the model. The numerical results not only demonstrate the feasibility of the model but also underscore the effectiveness of the control law in improving floater motion performance.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141393816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2730/1/012001
Wei Peng, Xuesong Li, Xiaodong Ren, Chunwei Gu, Xiaobin Que
Adjusting the trailing edge radius of the intake struts may be advantageous in suppressing the vibration of compressor rotor blades. To explore the impact of the intake struts trailing edge radius on the excitation force and vibration, this study focuses on a compressor with intake struts, and fluid and vibration calculations were conducted. The study revealed that decreasing the trailing edge radius led to a reduction in separation near the strut’s trailing edge, resulting in a narrower wake and weakened mixing near the trailing edge. This caused the total pressure loss region induced by the wake to become more elongated in the low-frequency component, leading to a nonlinear decrease in total pressure amplitude with the reduction of the trailing edge radius. As the trailing edge radius decreased, the excitation force and vibration amplitude of the first-stage compressor rotor blades decreased, while the excitation force distribution showed little variation. The research findings provide insights for the design of intake struts.
{"title":"Influence of trailing edge radius of intake struts on excitation force and vibration of rotor blades","authors":"Wei Peng, Xuesong Li, Xiaodong Ren, Chunwei Gu, Xiaobin Que","doi":"10.1088/1742-6596/2730/1/012001","DOIUrl":"https://doi.org/10.1088/1742-6596/2730/1/012001","url":null,"abstract":"Adjusting the trailing edge radius of the intake struts may be advantageous in suppressing the vibration of compressor rotor blades. To explore the impact of the intake struts trailing edge radius on the excitation force and vibration, this study focuses on a compressor with intake struts, and fluid and vibration calculations were conducted. The study revealed that decreasing the trailing edge radius led to a reduction in separation near the strut’s trailing edge, resulting in a narrower wake and weakened mixing near the trailing edge. This caused the total pressure loss region induced by the wake to become more elongated in the low-frequency component, leading to a nonlinear decrease in total pressure amplitude with the reduction of the trailing edge radius. As the trailing edge radius decreased, the excitation force and vibration amplitude of the first-stage compressor rotor blades decreased, while the excitation force distribution showed little variation. The research findings provide insights for the design of intake struts.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141397787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/9/092018
Ghanesh Narasimhan, D. Gayme, C. Meneveau
Reliable characterization of wind turbine wakes in the presence of Atmospheric Boundary Layer (ABL) flows is crucial to accurately predict wind farm performance. Wind veering in the ABL shears the wake in the lateral direction, and wind veer strength depends on the thermal stability of the ABL. Analytical wake modeling approaches must capture these ABL effects to ensure correct prediction of the wake structure under varied atmospheric conditions. To this end, a new physics-based analytical wake model is developed in this study that is capable of predicting the shape of wakes influenced by wind veer and thermal stratification effects. This model combines a novel ABL wind field model with the Gaussian wake model. The new ABL wind model is capable of predicting both the streamwise and spanwise velocity components in conventionally neutral (CNBL) and stable (SBL) ABL flows. The analytical expressions for both of these horizontal velocity components adhere to Monin-Obukhov Similarity Theory (MOST) in the surface layer, while capturing wind veering in the outer layer of the ABL. Incorporating this ABL model with the Gaussian wake model predicts laterally deflected wake shapes in a fully predictive and self-consistent fashion for a wide range of atmospheric conditions. The results also demonstrate that the enhanced wake model gives improved predictions relative to Large Eddy Simulations of power losses due to wake interactions under strongly stably stratified atmospheric conditions, where wind veer effects are dominant.
{"title":"Analytical Wake Modeling in Atmospheric Boundary Layers: Accounting for Wind Veer and Thermal Stratification","authors":"Ghanesh Narasimhan, D. Gayme, C. Meneveau","doi":"10.1088/1742-6596/2767/9/092018","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/9/092018","url":null,"abstract":"Reliable characterization of wind turbine wakes in the presence of Atmospheric Boundary Layer (ABL) flows is crucial to accurately predict wind farm performance. Wind veering in the ABL shears the wake in the lateral direction, and wind veer strength depends on the thermal stability of the ABL. Analytical wake modeling approaches must capture these ABL effects to ensure correct prediction of the wake structure under varied atmospheric conditions. To this end, a new physics-based analytical wake model is developed in this study that is capable of predicting the shape of wakes influenced by wind veer and thermal stratification effects. This model combines a novel ABL wind field model with the Gaussian wake model. The new ABL wind model is capable of predicting both the streamwise and spanwise velocity components in conventionally neutral (CNBL) and stable (SBL) ABL flows. The analytical expressions for both of these horizontal velocity components adhere to Monin-Obukhov Similarity Theory (MOST) in the surface layer, while capturing wind veering in the outer layer of the ABL. Incorporating this ABL model with the Gaussian wake model predicts laterally deflected wake shapes in a fully predictive and self-consistent fashion for a wide range of atmospheric conditions. The results also demonstrate that the enhanced wake model gives improved predictions relative to Large Eddy Simulations of power losses due to wake interactions under strongly stably stratified atmospheric conditions, where wind veer effects are dominant.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141391854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/4/042019
Muhammad Omer Siddiqui, Karin Eustorgi, P. Feja
Nacelle test benches offer the chance to identify any possible issues in the system design before conducting mandatory field testing for type certification. This can potentially reduce costs and time to market. However, nacelle system testing is an abstraction of the real system, as several interactions and interfaces between the nacelle and its environment are absent. Consequently, this has initiated research studies in recent years to fully understand the influence of these abstractions on the device under test. Extensive research has been conducted on the recently completed project Testfeld BHV to understand the influence of abstractions on the vibration response of the drivetrain. In this project, the Adwen AD8-180 has been the wind turbine under study that was tested first at a nacelle test bench, followed by field tests at a site in Germany. This paper presents the findings of these studies with regards to the drivetrain vibration response during nacelle tests and field tests. The similarities and differences observed in the drivetrain vibration response are highlighted, and reasons that lead to deviations in the vibration response are discussed. Furthermore, the work also presents a simulative framework that can aid the test bench’s ability to predict the correct field-like drivetrain vibration response prior to field tests.
{"title":"Comparison of Drivetrain Vibration Response During Field Operation and on a Nacelle Test Bench","authors":"Muhammad Omer Siddiqui, Karin Eustorgi, P. Feja","doi":"10.1088/1742-6596/2767/4/042019","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/4/042019","url":null,"abstract":"Nacelle test benches offer the chance to identify any possible issues in the system design before conducting mandatory field testing for type certification. This can potentially reduce costs and time to market. However, nacelle system testing is an abstraction of the real system, as several interactions and interfaces between the nacelle and its environment are absent. Consequently, this has initiated research studies in recent years to fully understand the influence of these abstractions on the device under test. Extensive research has been conducted on the recently completed project Testfeld BHV to understand the influence of abstractions on the vibration response of the drivetrain. In this project, the Adwen AD8-180 has been the wind turbine under study that was tested first at a nacelle test bench, followed by field tests at a site in Germany. This paper presents the findings of these studies with regards to the drivetrain vibration response during nacelle tests and field tests. The similarities and differences observed in the drivetrain vibration response are highlighted, and reasons that lead to deviations in the vibration response are discussed. Furthermore, the work also presents a simulative framework that can aid the test bench’s ability to predict the correct field-like drivetrain vibration response prior to field tests.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141391890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/9/092033
J. Schøler, N. Rosi, J. Quick, R. Riva, S. J. Andersen, J. P. Murcia Leon, M. P. van der Laan, P-E. Réthoré
Artificial Neural Networks (ANNs) are being applied as a faster alternative to Computational Fluid Dynamics (CFD) for wind turbine engineering wake models. Unfortunately, ANNs can fail to generalize if the data is insufficient. Physics-Informed Neural Networks (PINNs) can improve convergence while lowering the required data amounts. This paper investigates the PINN methodology systematically by considering varying amounts of data and physics collocation points. This work considers the rotationally symmetric Reynolds Averaged Navier-Stokes (RANS) formulation. Initially, a baseline fully data-driven ANN is studied to determine a suitable network size. Then, multiple PINN-based wake surrogates are trained with continuity and momentum conservation knowledge, varying amounts of data, and physics collocation points. It was found that including physics information under the best circumstances could improve accuracy by 18% at the cost of increasing the training time by a factor of 116. The findings imply that physics information can improve neural network based wake surrogates.
{"title":"RANS wake surrogate: Impact of Physics Information in Neural Networks","authors":"J. Schøler, N. Rosi, J. Quick, R. Riva, S. J. Andersen, J. P. Murcia Leon, M. P. van der Laan, P-E. Réthoré","doi":"10.1088/1742-6596/2767/9/092033","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/9/092033","url":null,"abstract":"Artificial Neural Networks (ANNs) are being applied as a faster alternative to Computational Fluid Dynamics (CFD) for wind turbine engineering wake models. Unfortunately, ANNs can fail to generalize if the data is insufficient. Physics-Informed Neural Networks (PINNs) can improve convergence while lowering the required data amounts. This paper investigates the PINN methodology systematically by considering varying amounts of data and physics collocation points. This work considers the rotationally symmetric Reynolds Averaged Navier-Stokes (RANS) formulation. Initially, a baseline fully data-driven ANN is studied to determine a suitable network size. Then, multiple PINN-based wake surrogates are trained with continuity and momentum conservation knowledge, varying amounts of data, and physics collocation points. It was found that including physics information under the best circumstances could improve accuracy by 18% at the cost of increasing the training time by a factor of 116. The findings imply that physics information can improve neural network based wake surrogates.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141403167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1088/1742-6596/2767/3/032015
Youssef E. Tohamy, Urs Giger, D. Marten, Horst Schulte
This paper presents a two-level control scheme for multi-rotor wind turbines. The first subordinate decentralized controller replaces the active pitch control with oversized generators that achieve the power limitation objective. In combination with this, the second higher-level controller mitigates the mechanical load on the main tower by adjusting the thrust forces acting on the side turbines through coordinated local torque control. The results proved that the decentralized controller managed to replace the pitch control by achieving the same power curve, and the load mitigation controller tended to equate the thrusts on both turbines, which mitigates the mechanical loads on the turbine tower. A high-fidelity QBlade model was developed and showed consistent results to the simplified model in SIMULINK.
{"title":"Multi-Rotor Wind Turbine Control: Strategies for Pitch Replacement and Mechanical Load Mitigation","authors":"Youssef E. Tohamy, Urs Giger, D. Marten, Horst Schulte","doi":"10.1088/1742-6596/2767/3/032015","DOIUrl":"https://doi.org/10.1088/1742-6596/2767/3/032015","url":null,"abstract":"This paper presents a two-level control scheme for multi-rotor wind turbines. The first subordinate decentralized controller replaces the active pitch control with oversized generators that achieve the power limitation objective. In combination with this, the second higher-level controller mitigates the mechanical load on the main tower by adjusting the thrust forces acting on the side turbines through coordinated local torque control. The results proved that the decentralized controller managed to replace the pitch control by achieving the same power curve, and the load mitigation controller tended to equate the thrusts on both turbines, which mitigates the mechanical loads on the turbine tower. A high-fidelity QBlade model was developed and showed consistent results to the simplified model in SIMULINK.","PeriodicalId":16821,"journal":{"name":"Journal of Physics: Conference Series","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141409180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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