气动噪声是高速行驶下汽车的主要噪声源,在组成气动噪声的三部分声源中,偶极子声源占主导地位,而偶极子声源又取决于车身表面脉动压力。应用双向流固耦合方法对汽车的表面脉动压力进行数值计算,利用CFX软件进行流场计算,ANSYS软件进行结构计算,以MFX-ANSYS/CFX为数据耦合平台,采用双向同步求解的方法,对流场和侧窗结构响应进行联合求解,并将耦合前后的计算结果与风洞试验进行对比。结果表明,流固耦合作用使得流场压力脉动增强,且车速越高,流固耦合作用对气动噪声的影响越大;与非耦合数值计算相比,耦合计算结果更接近试验值,具有更高的准确性。
Aerodynamic noise is the main noise source when automobile runs at high speed.The aerodynamic noise around automobiles was dominated by dipole source which depends on fluctuating pressure around automobiles.Flow field calculation was carried out using CFX software and structure calculation was carried out using ANSYS software,respectively.Based on MFX-ANSYS/CFX data coupling platform,two-way synchronization solution method was used to compute the flow field and the response of automobile's side window structure.The results show that,fluid-structure interaction enhances the flow field pressure pulsation,as the speed increases,the effects of fluid-structure interaction on aerodynamic noise become more intense.Compared with non-coupled numerical calculations,the coupling calculation results are closer to experimental values,and has a higher accuracy.