汽车空调风道气动噪声仿真方法研究

An Investigation into Simulation Method of Aerodynamic Noise in Vehicle HVAC Ducts

为寻求汽车空调风道气动噪声一种高效高精度的仿真方法,基于德国整车企业联合发布的标准风道模型,对比研究了声类比法、直接模拟法和联合仿真分析法的优劣,并重点分析了声源面对声类比法精度的影响。首先,采用RNG湍流模型与SST k-ωDES模型分别对其稳态流场与瞬态流场进行求解,然后采用声类比法、直接模拟法和联合仿真法分别求解远场辐射噪声问题,仿真与试验结果表明:RNG湍流模型捕捉的风道内时均流场特征与PIV测量结果基本吻合; SST k-ωDES模型求解的风道内壁面脉动压力频谱仿真值与试验值基本一致;而在常用的几种仿真方法中,以出风口处环绕射流的可穿透面为声源面的声类比法求解精度最优。

In order to find an efficient and high accuracy simulation method for the aerodynamic noise in vehicle HVAC duets, three commonly-used methods, i.e. acoustic analogy, direct simulation and co-simulation analysis methods are compared and the etchers of sound source surthee on the accuracy of acoustic analogy method are emphatically analyzed, based on the standard HVAC duet model co-issued by German vehicle manufacturers Audi, BMW, Daimler, Porsehe and Volkswagen. Firstly, RNG turbulence model and SST k-ω DES model are adopted to solve the steady state and transient flow fieht respectively. Then, the acoustic analogy, direct simulation and co-sim- ulation methods are used to calculate far fieht radiation noise respectively. The results of simulation and test show that the time-averaged characteristics of tlow-field in HVAC duet obtained with RNG turbulence model are overall agree with PIV measurement data and the fluctuated pressure spectra on duet wall surfaces simulated by SST k-ω DES model are basically consistent with test results. Among commonly-used simulation methods, the acoustic analogy method with the penetrable surrace surrounding the jet turbulence at duet outlet as sound source surface has the highest accuracy.