In a large wind farm,the wakes of upstream and downstream wind turbines can interfere with each other,affecting the overall power output of the wind farm.To further improve the numerical accuracy of the turbine wake d...In a large wind farm,the wakes of upstream and downstream wind turbines can interfere with each other,affecting the overall power output of the wind farm.To further improve the numerical accuracy of the turbine wake dynamics under atmosphere turbulence,this work proposes some improvements to the actuator line-large-eddy simulation(AL-LES)method.Based on the dynamic k-equation large-eddy simulation(LES),this method uses a precursor method to generate atmospheric inflow turbulence,models the tower and nacelle wakes,and improves the body force projection method based on an anisotropic Gaussian distribution function.For these three improvements,three wind tunnel experiments are used to validate the numerical accuracy of this method.The results show that the numerical results calculated in the far-wake region can reflect the characteristics of typical onshore and offshore wind conditions compared with the experimental results.After modeling the tower and nacelle wakes,the wake velocity distribution is consistent with the experimental result.The radial migration velocity of the tip vortex calculated by the improved blade body force distribution model is 0.32 m/s,which is about 6%different from the experimental value and improves the prediction accuracy of the tip vortex radial movement.The method proposed in this paper is very helpful for wind turbine wake dynamic analysis and wind farm power prediction.展开更多
A hybrid method is presented to numerically investigate the wind turbine aerodynamic characteristics.The wind turbine blade is replaced by an actuator line model.Turbulence is treated using a dynamic one-equation subg...A hybrid method is presented to numerically investigate the wind turbine aerodynamic characteristics.The wind turbine blade is replaced by an actuator line model.Turbulence is treated using a dynamic one-equation subgrid-scale model in large eddy simulation.Detailed information on the basic characteristics of the wind turbine wake is obtained and discussed.The rotor aerodynamic performance agrees well with the measurements.The actuator line method large-eddy simulation(ALM-LES)technique demonstrates its high potential in providing accurate load prediction and high resolution of turbulent fluctuations in the wind turbine wakes and the interactions within a feasible cost.展开更多
In numerical simulations of tidal current farms,large-scale computational fluid dynamic(CFD)simulations with a high-resolution grid are required to calculate the interactions between tidal turbines.In this study,we de...In numerical simulations of tidal current farms,large-scale computational fluid dynamic(CFD)simulations with a high-resolution grid are required to calculate the interactions between tidal turbines.In this study,we develop a numerical simulation method for tidal current turbines using the lattice Boltzmann method(LBM),which is suitable for large-scale CFD simulations.Tidal turbines are modeled by using the actuator line(ACL)model,which represents each blade as a group of actuator points in a line.In order to validate our LBM-ACL model,we perform simulations for two interacting tidal turbines,and results of turbine performance are compared with a water tank experiment.The proposed model successfully reproduces the variation of the torque due to wave effects and mean turbine performance.We have demonstrated a large-scale simulation for ten tidal turbines using 8.55×10^(8) grid points and 16 GPUs of Tesla P100 and the simulation has been completed within 9 hours with the LBM performance of 392 MLUPS per GPU.展开更多
Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid regions.Therefore...Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid regions.Therefore,the relationship between sanddust weather environments and wind turbine operations has garnered significant attention.To investigate the impact of wind turbine wakes on sand-dust transportation,this study employs large eddy simulation to model flow fields,coupled with an actuator line model for simulating rotating blades and a multiphase particle in cell model for simulating sand particles.The research focuses on a horizontal axis wind turbine model and examines the motion and spatiotemporal distribution characteristics of four typical sizes of sand particles in the turbine wake.The findings reveal that sand particles of varying sizes exhibit a spiral settling pattern after traversing the rotating plane of wind turbine blades,influenced by blade shedding vortex and gravity.Sand particles tend to cluster in the peripheries of the vortex cores of low vorticity in the wind turbine wake.The rotation of wind turbines generates a wake vortex structure that causes a significant clustering of sand particles at the tip vortex.As the wake distance increases,the particles that cluster at the turbine's tip gradually spread outward to approximately twice the rotor diameter and then begin to mix with the incoming flow environment.Wind turbines have a noticeable impact on sand-dust transportation,hindering their movement to a significant extent.The average sand-blocking rate exhibits a trend of initially increasing and then decreasing as the wake distance increases.At its peak,the sand-blocking rate reaches an impressive 67.55%.The presence of wind turbines induces the advanced settling of sand particles,resulting in a“triangular”distribution of the deposition within the ground projection area of the wake.展开更多
基金Project supported by the National Key Research and Development Program of China(Nos.2019YFE0192600,2017YFE0132000,and 2019YFB1503700)the National Natural Science Foundation of China(Nos.51761135012 and 11872248)。
文摘In a large wind farm,the wakes of upstream and downstream wind turbines can interfere with each other,affecting the overall power output of the wind farm.To further improve the numerical accuracy of the turbine wake dynamics under atmosphere turbulence,this work proposes some improvements to the actuator line-large-eddy simulation(AL-LES)method.Based on the dynamic k-equation large-eddy simulation(LES),this method uses a precursor method to generate atmospheric inflow turbulence,models the tower and nacelle wakes,and improves the body force projection method based on an anisotropic Gaussian distribution function.For these three improvements,three wind tunnel experiments are used to validate the numerical accuracy of this method.The results show that the numerical results calculated in the far-wake region can reflect the characteristics of typical onshore and offshore wind conditions compared with the experimental results.After modeling the tower and nacelle wakes,the wake velocity distribution is consistent with the experimental result.The radial migration velocity of the tip vortex calculated by the improved blade body force distribution model is 0.32 m/s,which is about 6%different from the experimental value and improves the prediction accuracy of the tip vortex radial movement.The method proposed in this paper is very helpful for wind turbine wake dynamic analysis and wind farm power prediction.
基金funded jointly by the National Basic Research Program of China(″973″Program)(No.2014CB046200)the Jiangsu Provincial Natural Science Foundation(No.BK20140059)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(No.11172135)the EU Seventh Framework Program(No.FP7-PEOPLE-2010-IRSES-269202)
文摘A hybrid method is presented to numerically investigate the wind turbine aerodynamic characteristics.The wind turbine blade is replaced by an actuator line model.Turbulence is treated using a dynamic one-equation subgrid-scale model in large eddy simulation.Detailed information on the basic characteristics of the wind turbine wake is obtained and discussed.The rotor aerodynamic performance agrees well with the measurements.The actuator line method large-eddy simulation(ALM-LES)technique demonstrates its high potential in providing accurate load prediction and high resolution of turbulent fluctuations in the wind turbine wakes and the interactions within a feasible cost.
基金This work was supported by the JSPS KAKENHI(Grant No.JP19H02363).The computation was carried out using the computer resource offered under the category of General Projects by Research Institute for Information Technology,Kyushu University.
文摘In numerical simulations of tidal current farms,large-scale computational fluid dynamic(CFD)simulations with a high-resolution grid are required to calculate the interactions between tidal turbines.In this study,we develop a numerical simulation method for tidal current turbines using the lattice Boltzmann method(LBM),which is suitable for large-scale CFD simulations.Tidal turbines are modeled by using the actuator line(ACL)model,which represents each blade as a group of actuator points in a line.In order to validate our LBM-ACL model,we perform simulations for two interacting tidal turbines,and results of turbine performance are compared with a water tank experiment.The proposed model successfully reproduces the variation of the torque due to wave effects and mean turbine performance.We have demonstrated a large-scale simulation for ten tidal turbines using 8.55×10^(8) grid points and 16 GPUs of Tesla P100 and the simulation has been completed within 9 hours with the LBM performance of 392 MLUPS per GPU.
基金supported by the National Key Research&Development Program of China(Grant Nos.2022YFB4202102,and 2022YFB4202104)the National Natural Science Foundation of China(Grant Nos.52166014,and 52276197)+1 种基金the Science Fund for Creative Research Groups of Gansu Province(Grant No.21JR7RA277)the Hongliu Outstanding Young Talents Program of Lanzhou University of Technology。
文摘Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid regions.Therefore,the relationship between sanddust weather environments and wind turbine operations has garnered significant attention.To investigate the impact of wind turbine wakes on sand-dust transportation,this study employs large eddy simulation to model flow fields,coupled with an actuator line model for simulating rotating blades and a multiphase particle in cell model for simulating sand particles.The research focuses on a horizontal axis wind turbine model and examines the motion and spatiotemporal distribution characteristics of four typical sizes of sand particles in the turbine wake.The findings reveal that sand particles of varying sizes exhibit a spiral settling pattern after traversing the rotating plane of wind turbine blades,influenced by blade shedding vortex and gravity.Sand particles tend to cluster in the peripheries of the vortex cores of low vorticity in the wind turbine wake.The rotation of wind turbines generates a wake vortex structure that causes a significant clustering of sand particles at the tip vortex.As the wake distance increases,the particles that cluster at the turbine's tip gradually spread outward to approximately twice the rotor diameter and then begin to mix with the incoming flow environment.Wind turbines have a noticeable impact on sand-dust transportation,hindering their movement to a significant extent.The average sand-blocking rate exhibits a trend of initially increasing and then decreasing as the wake distance increases.At its peak,the sand-blocking rate reaches an impressive 67.55%.The presence of wind turbines induces the advanced settling of sand particles,resulting in a“triangular”distribution of the deposition within the ground projection area of the wake.