某SUV后视镜降噪设计与风洞试验验证

Noise Reduction Design and Wind Tunnel Test Verification of an SUV Rearview Mirror

为研究后视镜镜臂对其产生的气动噪声的影响,针对某SUV后视镜采用脱体涡(detached eddy simulation)方法分析其流场和近场噪声特性。通过改变镜臂外形设计了两种降噪模型,在航空工业气动院FL-53风洞开展了3个后视镜模型的气动噪声风洞试验。结果显示:通过改变镜臂周围曲率,能够减小涡的尺度,改变涡脱落的方向,降低后视镜尾流区域近场噪声,且风速会影响部分频段的降噪效果;从远场指向性看,3个后视镜在尾流区声压级较大,降噪模型没有改变远场指向性。

To investigate the effect of automobile rearview mirror arm on the aero-acoustics,based on a certain SUV automobile rearview mirror,the detached eddy simulation method is used to analyze the flow field and near field noise characteristics.By changing the shape of the arm,two kinds of noise-reduction models are designed,and the aerodynamic noise wind tunnel tests of three rearview mirror models are carried out in the FL-53 aero-acoustic wind tunnel of the Institute of Aerodynamics of the Aviation Industry.The results show that by changing the curvature around the mirror arm,the size of detached eddy is reduced,the direction of vortex shedding is changed,and the noise near the wake zone is reduced.Besides,the wind velocity can affect the noise reduction in some frequency bands.In terms of far-field directivity,the sound pressure level of the three rear-view mirrors in the wake flow field is larger,and the noise reduction models cannot change the far-field directivity.