Numerical simulations of wind turbine blade-tower interaction by using the open source OpenFOAM tools coupled with arbitrary mesh interface （AMI） method were presented. The governing equations were the unsteady Reyn...Numerical simulations of wind turbine blade-tower interaction by using the open source OpenFOAM tools coupled with arbitrary mesh interface （AMI） method were presented. The governing equations were the unsteady Reynolds-averaged Navier-Stokes （RANS） which were solved by the pimpleDyMFoam solver, and the AMI method was employed to handle mesh movements. The National Renewable Energy Laboratory （NREL） phase VI wind turbine in upwind configuration was selected for numerical tests with different incoming wind speeds （5, 10, 15, and 25 m/s） at a fixed blade pitch and constant rotational speed. Detailed numerical results of vortex structure, time histories of thrust, and pressure distribution on the blade and tower were presented. The findings show that the wind turbine tower has little effect on the whole aerodynamic performance of an upwind wind turbine, while the rotating rotor will induce an obvious cyclic drop in the front pressure of the tower. Also, strong interaction of blade tip vortices with separation from the tower was observed.展开更多
This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximate...This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximated by fiat elements in which the membrane effects are evaluated using the FF （free formulation） finite element and the flexure effects are calculated using DKT （discrete shear triangle） finite element. The user-friendly system is implemented using OpenGL library to provide the graphical construction for geometry, mesh orientation, and other requirements of the finite element model. For the processing stage is built a specific dll library implemented in C＋＋ language for the analysis using the FF and DKT finite elements. The post-processing stage is build using specific dialogs box to present all results. The displacement results are visualized in the graphic interface to show the static and dynamic deformations of the tower. Some examples are presented to show all the tasks of the parametric tool.展开更多
The development of offshore wind energy is fast as it is clean, safe and of high efficiency. The harsh marine environment raises high demand on the foundation design of offshore wind turbine. Earthquake loading is one...The development of offshore wind energy is fast as it is clean, safe and of high efficiency. The harsh marine environment raises high demand on the foundation design of offshore wind turbine. Earthquake loading is one of the most significant factors which should be considered in the design phase. In this paper, a group of earthquake centrifuge tests were conducted on a physical wind turbine model with tripod foundation. The seismic responses of both wind turbine model and foundation soil were analyzed in terms of the recorded accelerations, pore water pressures, lateral displacements and settlements. The results were also compared with those measured in the previous research on mono-pile foundation. It is demonstrated that the tripod foundation can provide better resistance in the lateral displacement and structural settlement under earthquake loading.展开更多
To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated accordi...To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects, and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.50739004 and 11072154.
文摘Numerical simulations of wind turbine blade-tower interaction by using the open source OpenFOAM tools coupled with arbitrary mesh interface （AMI） method were presented. The governing equations were the unsteady Reynolds-averaged Navier-Stokes （RANS） which were solved by the pimpleDyMFoam solver, and the AMI method was employed to handle mesh movements. The National Renewable Energy Laboratory （NREL） phase VI wind turbine in upwind configuration was selected for numerical tests with different incoming wind speeds （5, 10, 15, and 25 m/s） at a fixed blade pitch and constant rotational speed. Detailed numerical results of vortex structure, time histories of thrust, and pressure distribution on the blade and tower were presented. The findings show that the wind turbine tower has little effect on the whole aerodynamic performance of an upwind wind turbine, while the rotating rotor will induce an obvious cyclic drop in the front pressure of the tower. Also, strong interaction of blade tip vortices with separation from the tower was observed.
文摘This work deals with a description of a parametric tool for elastic analysis of wind turbine tower, incorporating all analysis steps （preprocessing, processing and post-processing）. The tower geometry is approximated by fiat elements in which the membrane effects are evaluated using the FF （free formulation） finite element and the flexure effects are calculated using DKT （discrete shear triangle） finite element. The user-friendly system is implemented using OpenGL library to provide the graphical construction for geometry, mesh orientation, and other requirements of the finite element model. For the processing stage is built a specific dll library implemented in C＋＋ language for the analysis using the FF and DKT finite elements. The post-processing stage is build using specific dialogs box to present all results. The displacement results are visualized in the graphic interface to show the static and dynamic deformations of the tower. Some examples are presented to show all the tasks of the parametric tool.
文摘The development of offshore wind energy is fast as it is clean, safe and of high efficiency. The harsh marine environment raises high demand on the foundation design of offshore wind turbine. Earthquake loading is one of the most significant factors which should be considered in the design phase. In this paper, a group of earthquake centrifuge tests were conducted on a physical wind turbine model with tripod foundation. The seismic responses of both wind turbine model and foundation soil were analyzed in terms of the recorded accelerations, pore water pressures, lateral displacements and settlements. The results were also compared with those measured in the previous research on mono-pile foundation. It is demonstrated that the tripod foundation can provide better resistance in the lateral displacement and structural settlement under earthquake loading.
基金supported by the National Natural Science Foundation of China (No. 50708015)the Program for New Century Excellent Talents in University (No. NCET-06-0270), China
文摘To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects, and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.
