风力机叶片表面压力的计算与外场测试分析

Measurement and calculation of blade surface pressure for a wind turbine in field

研究在外场工况下,对风力机叶片表面压力的测试方法,并将测试结果与CFD计算结果进行比较。为了获取叶片在外场非稳态工况下的压力信息,沿叶片展向选取7个典型段面布置带式压力传感器。在数值计算中,通过数码扫描得到试验翼型的几何形状并建立计算模型,用非压缩的N-S方程和SSTk-ω湍流模型耦合,分别对7个翼型的气动性能进行计算。通过对试验和计算结果的对比发现,因为三维旋转效应的存在,基于动量-叶素理论的二维翼型计算常常低估了实际风轮动力的产生,旋转叶轮表面压力分布和二维翼型计算结果明显不同。

A measurement method of the blade surface pressures for a wind turbine in field is given and the measured data are compared with the CFD calculation results in this paper. For the field experiment, the belt sensors were mounted on seven sections along the blade to collect the pressure signals in unsteady environment. For the calculation, the incompressible N-S equations coupled with the SST k-w turbulence model are solved to obtain the aerodynamic performance of the tested blade airfoils, whose geometric shapes have been determined from digital scanning. From the comparison between the experiment and calculation, it is demonstrated that the pres sure distribution on the rotational blade appears obviously different from the two-dimensional air- foil data due to the three dimensional rotational effect and validated that the wind turbine power output could be underestimated if the two-dimensional airfoil aerodynamic data based on the blade momentum theory are used.