汽车空调气动噪声数值与试验研究

Experimental and Numerical Investigations of Aerodynamic Noise for Automotive Airconditioning

摘要:

通过数值仿真和台架试验相结合的方法开展某车型空调系统气动噪声研究.研究发现，精细网格和大涡模拟方法能够获得高精度的出风口风量分配结果，它们与试验最大偏差为4.35%，最小偏差为0.93%.与此同时，空间流线的紊乱和当地速度的大小直接影响其表面总声压级的大小，对于计算的空调系统，风机是主要噪声源，改善风机流动分离，降低风机噪声是空调系统降噪的关键.可穿透面的声辐射方法有效地考虑到表面压力脉动的偶极子噪声和空间涡流的四极子噪声，是汽车空调气动噪声计算中声辐射的有效处理方法.利用该方法得到的测点总声压级与试验值更加接近，约相差2 dBA，频谱变化趋势和数值基本一致，推荐作为后续空调气动噪声仿真的声辐射处理方法.

Abstract:

The aerodynamic noise of automotive airconditioning was investigated by numerical and experimental methods. Results show that highprecision outlet air distribution results can be obtained by the fine mesh and large eddy simulation method. The maximum deviation is 4.35% and the minimum deviation is 0.93%. The total sound pressure level of surface is dependent on the local velocity and the disorder of pathlines. The fan is the main sound source of the automotive airconditioning, and the key to reduce the fan noise by improving the flow separation of fan. Permeable surface sound propagation method effectively considers dipole source generated by the surface pressure fluctuation and quadrupole source generated by vortex. It is an effective treatment method to calculate the aerodynamic noise of automotive air conditioning. The total sound pressure level of test points obtained by the method are closer to the experimental values. The difference between them is 2 dBA and the tendency of the spectrum is consistent, which can be recommended as the sound propagation method of aerodynamic noise simulation.