旋转对风力涡轮叶片三维边界层影响的数值计算

由于旋转的影响，基于经典二维叶素理论设计的水平轴风力涡轮叶片，在高风速工况下不能可靠运行，即存在失速延迟现象，采用不可压缩三维边界层积分方程揭示产生这种失速延迟现象的机理，分析旋转对风力涡轮边界层的影响，通过积分边界层方程的求解（包括层流，转捩及紊流），得到一些关键的影响参数（如失速点位置，动量厚度等）。并在相同的运行条件下，比较二维工况与三维旋转工况下各关键参数的差别，得到由于旋转的影响，边界层

EFFECT OF ROTATION ON BLADE BOUNDARY LAYER OF WIND TURBINE

Nowadys,design and analysis methods for wind turbines are generally based on relatively simple models of rotor blade aerodynamics,such as 2 D blade element/momentum theory(BEMT).However,more accurate field investigations over the past few years showed discrepancies between predicted and measured performance,owing to the effect of rotation on the wind turbine blade boundary layer distribution.In this paper,the effect of rotation on the blade boundary layer of wind turbine is described and 3 D incompressible steady momentum integral boundary layer equations are employed to study this complex problem.By solving the 3 D integral boundary layer equations with the assumed velocity profiles and a closure of model(including both laminar and the turbulent boundary layer models),the effects of rotation on blade boundary layers are investigated.Several key parameters,such as separation position and momentum thickness,are calculated and compared for the rotating and non rotation cases.It is concluded that the stall is postponed due to rotation and the separation point is delayed with the increasing rotation speed or decreasing the blade spanwise position.Possible modifications which should be considered to existing 2 D BEMT methods are suggested.