基于直接CAA与SEA的汽车风噪预测与控制

本文中对某一SUV风噪的预测与控制进行研究.首先基于风洞测试进行风噪声源特性与传递路径的分析,发现泄漏噪声主要发生在500 Hz以上中高频段,车底风噪主要集中于800 Hz以下中低频段,而在外形噪声中,由车顶和四门传递的风噪的贡献大于翼子板.然后基于气动噪声直接计算法和统计能量分析对外形噪声进行仿真,并结合风洞测试分析...

Vehicle Wind Noise Prediction and Control Based on Direct CAA and SEA

The prediction and control on the wind noise of a SUV is studied in this paper.Firstly,the char?acteristics of wind noise source and transmission path are analyzed based on wind tunnel test,and it is found that the leakage noise is mainly produced in the mid?to?high frequency range above 500 Hz,the underbody wind noise is mainly concentrated in the mid?to?low frequency range below 800 Hz,while for outer shape noise,the contribution of wind noise transmitted by the roof and four doors is higher than that of the fender.Then the shape noise is simulat?ed based on the aeroacoustics direct calculation and statistical energy analysis,and the influence of turbulence mod?el,mesh size and wave number analysis mode on the accuracy of wind noise simulation is analyzed by combining wind tunnel test.The results show that the attenuation of high?frequency wind noise with large eddy simulation(LES)is less than that with improved delayed detached eddy simulation(IDDES),and both the accuracy and the calculation efficiency of high?frequency wind noise simulation with LES are higher than that with IDDES.The com?parison of different mesh size within the allowable range of computing resources indicate that with the smallest mesh size of 2 mm,the cut?off frequency of the sound pressure level at side window can reach up to 2000 Hz.As for the modes of wavenumber analysis,the single?area wavenumber analysis underestimates the energy of mid?to?low fre?quency wind noise with low accuracy,while in multi?area wavenumber analysis,the area with lower sound energy has less influence on simulation accuracy.Finally,based on contribution analysis,two improving schemes are proposed:reducing the thickness of the support arm of rearview mirror and installing the rearview mirror on the door.As a result,with two improving schemes the overall sound pressure level in the vehicle is reduced by 1.38 and 1.93 dB,and the speech articulation is increased by 0.4%and 1.1%respectively.