基于积分方法的二维平行剪切层声远场预测

FAR SOUND FIELD PREDICTION OF A 2-D PARALLEL SHEAR LAYER BASING ON AN INTE- GRATION METHODOLOGY

本文采用二维Ffowcs Williams＆Hawkings(FW-H)方程对平行剪切层远声场辐射特性进行了研究。近流场时间精确数据通过计算气动声学(Computational Aeroacoustics,CAA)技术数值模拟获得,声远场信息则通过FW-H方程对近流场内的可穿透积分面进行积分获得。该方法首先采用具有解析解的涡/尾缘干涉问题进行了校核,进一步采用CAA/FW-H匹配技术对二维平行剪切层声辐射问题进行了预测,计算结果表明,积分解与计算域内的CAA数值解吻合较好。

The far sound field of a 2-D parallel shear layer is studied basing on the Ffowcs Williams & Hawkings(FW-H) Equation. The time accurate near flow field data are numerically simulated by a Computational Aeroacoustics (CAA) technique. Then the far sound field information is calculated from a near field penetrable surface through FW-H integration. This procedure is firstly validated by vortex/trailing edge interaction problem with an analytical solution. Furthermore, the sound radiation from a 2-D parallel shear layer is predicted by the CAA/FW-H matching technique. Numerical results show that the integration results agree rather well with CAA solutions.