非对称钝尾缘翼型气动噪声数值研究

Numerical Study on Aerodynamic Noise of an Asymmetric Airfoil with Blunt Trailing Edge

为得到具有高气动性能、低噪声水平的风力机专用翼型,基于参数化非对称钝尾缘翼型,研究了尾缘厚度及其分配比对风力机翼型气动性能及气动噪声的影响。采用分离涡模拟方法和声学类比方程建立了噪声预测方法,针对改型翼型进行样条函数参数化处理,并计算其气动噪声。结果表明:随着尾缘厚度的增加,改型翼型的升力系数和升阻比均大于原始翼型,气动性能得到明显改善;钝尾缘翼型会导致气动噪声增加,当尾缘厚度为1.5%c、尾缘厚度分配比为1∶3时,翼型气动噪声增幅较小。

To get a special airfoil for the wind turbine with high aerodynamic performance and low noise level,based on the parameterized asymmetric airfoil with blunt trailing edge,a study was conducted on the influence of trailing edge thickness and its distribution ratio on the aerodynamic performance and aerodynamic noise of the wind turbine airfoil.A noise prediction method was established using detached eddy simulation and acoustic analogy equation,and the aerodynamic noise was calculated by parametric processing of the asymmetric airfoil modified by spline function.Results show that both the lift coefficient and lift-drag ratio of the modified airfoil are greater than those of original airfoil with the increase of trailing edge thickness,while the aerodynamic performance is improved obviously.Blunt trailing edge helps to raise the aerodynamic noise of the airfoil;however,at the trailing edge thickness of 1.5%chord length and with the distribution ratio of 1∶3,the increase of aerodynamic noise is relatively small.