三维旋转效应对桨叶气动特性影响的计算

在旋转的作用下,流动分离向下游延迟,结果大大改变了风力机桨叶的气动特性,这种由旋转所带来的影响被称为三维旋转效应。本文以桨叶表面边界层理论分析的结果为基础,给出了三维旋转效应对气流分离影响的解析关系,将其与非定常气动和动态失速模型相结合,并适当考虑旋转条件下桨叶翼型载荷的分布特性,使其能计算三维旋转效应下风力机桨叶的非定常气动特性.通过算例表明,当这一三维旋转效应模型与非定常动态失速模型耦合后再计算桨叶非定常气动特性时,能大大改善计算结果。

Prediction of three-dimensional rotational effect on blade aerodynamic characteristics

The flow separation is delayed by rotation,which changes the blade aerodynamic characteristics greatly compared to its non-rotating counterpart.This phenomenon caused by rotation is called three-dimensional(3-D) rotational effect.Using the results of the 3-D integral boundary layer equations,this paper gives an analytical relationship between the 3-D rotational effect and the flow separation.Subsequently,this 3-D method is coupled to an unsteady aerodynamic and dynamic stall model to calculate unsteady aerodynamic characteristics of blade under the influence of the 3-D effects.The calculated results show that the approach presented in this article dramatically improves the prediction of the unsteady airloads on blades by including the 3-D rotational effect.