基于LES与FW-H方程的圆柱-翼型干涉噪声数值研究

采用大涡模拟（LES）结合Ffowcs Williams-Hawkings（FW-H）方程研究了圆柱-翼型干涉噪声的频谱特征和四极子噪声的影响.流场结果与实验吻合较好，声场获得了与实验相一致的频谱形状，翼型前缘30%弦长为主要干涉噪声源.针对计算与实验展向高度不同的问题，首先基于相关函数为三角函数的假定推导了展向修正公式，并与相关文献采用矩形函数、指数函数及高斯函数所得结果进行了对比.结果表明:不同的修正方法修正量差别高达7.6dB，三角函数与矩形函数修正效果类似，优于高斯函数，指数函数修正效果最差.分别采用固体壁面和可穿透数据面作为积分面，研究了体声源的影响，结果表明低马赫数下四极子噪声的影响可以忽略不计. 

Investigation of rod-airfoil interaction noise using large eddy simulation and FW-H equation

Large eddy simulation (LES) and Ffowcs Williams-Hawkings (FW-H) equation were used to investigate the spectral characteristics of the rod-airfoil interaction noise and the influence of the quadrupole source. The flow field prediction was in good agreement with experiment data, and the spectral shape of the acoustic radiation was consistent with experiment results. The front 30% chord length at the leading edge of the airfoil is the main interaction noise source. For the reason of the different span-wise length between simulation and experiment, a new group of formulas was derived based on the hypothesis of trigonometric correction function and the results were compared with the rectangular, exponential and Gaussian functions. The correction deviation for different correction methods is as large as 7.6 dB. The correction effect of the trigonometric function is similar to the rectangular function and better than Gaussian function, whilst the exponential function has the poorest correction effect. Solid wall surfaces and permeable data surfaces were used for acoustic calculation to investigate the effect of quadrupole source. The results show that the impact of quadrupole source is negligible at low Mach number.