The full two-dimensional Navier-Stokes algorithm and the SST k-? turbulence model were used to investigate incom-pressible viscous flow past the wind turbine two-dimensional airfoil under clean and roughness surface c...The full two-dimensional Navier-Stokes algorithm and the SST k-? turbulence model were used to investigate incom-pressible viscous flow past the wind turbine two-dimensional airfoil under clean and roughness surface conditions. The NACA 63-430 airfoil is chosen to be the subject, which is widely used in wind turbine airfoil and generally located at mid-span of the blade with thickness to chord length ratio of about 0.3. The numerical simulation of the airfoil under clean surface condition has been done. As a result, the numerical results had a good consistency with the experimental data. The wind turbine blade surface dust accumulation according to the operational periods in natural environment has been taken into consideration. Then, the lift coefficients and the drag coefficients of NACA 63-430 airfoil have been computed under different roughness heights, different roughness areas and different roughness locations. The role that roughness plays in promoting premature transition to turbulence and flow separation has been verified by the numeri-cal results. The trends of the lift coefficients and the drag coefficients with the roughness height and roughness area increasing have been obtained. What’s more, the critical values of roughness height, roughness area, and roughness location have been proposed. Furthermore, the performance of the airfoil under different operational periods has been simulated, and an advice for the period of cleaning wind turbine blades is proposed. As a result, the numerical simula-tion method has been verified to be economically available for investigation of the dust effect on wind turbine airfoils.展开更多
The wind energy resource is considerably rich in the deep water of China South Sea,where wind farms have to face the challenge of extreme typhoon events.In this work,the typhoon effect on the aerodynamic performance o...The wind energy resource is considerably rich in the deep water of China South Sea,where wind farms have to face the challenge of extreme typhoon events.In this work,the typhoon effect on the aerodynamic performance of the 5MW OC3-Hywind floating offshore wind turbine(FOWT)system has been investigated,based on the Aero-Hydro-Servo-Elastic FAST code.First,considering the full field observation data of typhoon“Damrey”is a long duration process with significant turbulence and high wind speed,so one 3-h representative truncated typhoon wind speed time history has been selected.Second,the effects of both the(variable-speed and collective-pitch)control system of NREL 5 MW wind turbine and the motion of the floating platform on the blade aerodynamic performance of the FOWT system during the representative typhoon time history has been investigated,based on blade element momentum(BEM)theory(coupled with potential theory for the calculation of the hydrodynamic loads of the Spar platform).Finally,the effects of different wind turbine control strategies,control parameter(KP-KI)combinations,wave heights and parked modes on the rotor aerodynamic responses of the FOWT system have been clarified.The extreme typhoon event can result in considerably large extreme responses of the rotor thrust and the generated power due to the possible blade pitch angle error phenomenon.One active-parked strategy has been proposed for reducing the maximum aerodynamic responses of the FOWT system during extreme typhoon events.展开更多
文摘The full two-dimensional Navier-Stokes algorithm and the SST k-? turbulence model were used to investigate incom-pressible viscous flow past the wind turbine two-dimensional airfoil under clean and roughness surface conditions. The NACA 63-430 airfoil is chosen to be the subject, which is widely used in wind turbine airfoil and generally located at mid-span of the blade with thickness to chord length ratio of about 0.3. The numerical simulation of the airfoil under clean surface condition has been done. As a result, the numerical results had a good consistency with the experimental data. The wind turbine blade surface dust accumulation according to the operational periods in natural environment has been taken into consideration. Then, the lift coefficients and the drag coefficients of NACA 63-430 airfoil have been computed under different roughness heights, different roughness areas and different roughness locations. The role that roughness plays in promoting premature transition to turbulence and flow separation has been verified by the numeri-cal results. The trends of the lift coefficients and the drag coefficients with the roughness height and roughness area increasing have been obtained. What’s more, the critical values of roughness height, roughness area, and roughness location have been proposed. Furthermore, the performance of the airfoil under different operational periods has been simulated, and an advice for the period of cleaning wind turbine blades is proposed. As a result, the numerical simula-tion method has been verified to be economically available for investigation of the dust effect on wind turbine airfoils.
基金This research was supported by the Fundamental Re-search Funds for the Central Universities and National Nat-ural Science Foundation of China(grant NO.51709040,51761135011,51651902).
文摘The wind energy resource is considerably rich in the deep water of China South Sea,where wind farms have to face the challenge of extreme typhoon events.In this work,the typhoon effect on the aerodynamic performance of the 5MW OC3-Hywind floating offshore wind turbine(FOWT)system has been investigated,based on the Aero-Hydro-Servo-Elastic FAST code.First,considering the full field observation data of typhoon“Damrey”is a long duration process with significant turbulence and high wind speed,so one 3-h representative truncated typhoon wind speed time history has been selected.Second,the effects of both the(variable-speed and collective-pitch)control system of NREL 5 MW wind turbine and the motion of the floating platform on the blade aerodynamic performance of the FOWT system during the representative typhoon time history has been investigated,based on blade element momentum(BEM)theory(coupled with potential theory for the calculation of the hydrodynamic loads of the Spar platform).Finally,the effects of different wind turbine control strategies,control parameter(KP-KI)combinations,wave heights and parked modes on the rotor aerodynamic responses of the FOWT system have been clarified.The extreme typhoon event can result in considerably large extreme responses of the rotor thrust and the generated power due to the possible blade pitch angle error phenomenon.One active-parked strategy has been proposed for reducing the maximum aerodynamic responses of the FOWT system during extreme typhoon events.
