使用IDDES方法预测飞行速度对喷流噪声的影响

摘要

使用变网格尺度定义的IDDES方法,预测了飞行速度对喷流噪声的影响.分析具有试验数据的喷流状态(Ma=0.9,基于喷管直径D的ReD=1.1×106),通过与试验结果的对比,验证方法的正确性,并做了网格敏感性分析,对比了不同FW-H方程积分面对结果的影响.增加自由来流马赫数会增加喷流势流核的长度,降低势流核结束位置的湍动能,降低远场噪声辐射.对远场噪声的影响规律与试验测量值相符,说明此方法适用于存在飞行速度的喷流噪声问题的预测.%This definition takes the direction of the vorticity into account and can accelerate the transition from Reynolds-averaged Navier-Stokes (RANS)region to large-eddy-simulation (LES)region.An isolated jet with Mach number of 0.9 and Reynolds number of 1.1 million based on the nozzle diameter is simulated.The flow quantities and noise from two meshes are compared. The two meshes both provide reasonable results,but the results from the fine mesh are closer to the measurements.Beside noise from five integral surfaces of dense mesh are compared.It is proved that the numerical methods are competent to predict jet-noise.When the freestream Mach number increases to 0.2,the length of potential core increases and the turbulent kinetic energy (TKE)and the far-field noise decrease.The changes of far-field noise due to flight velocity by our simulations are similar to the measurements.This method can be extended to predict flight velocity effects on jet noise.