汽车外场气动噪声仿真与计算

摘要

A distant point noise of car outfield is simulated and calculated with software FLUENT： through the steady-state calculation obtains the surface acoustic power and noise sources distribution of the car body and analyzes qualitatively the noise sources; by means of transient calculations gets the sound pressure spectrum of the car outfield noise in a point. The simulation results show that the outfield aerodynamic noise sources mainly come from the front area of car, rear-view mirror, the front windscreen and front wheel; and the far field acoustic pressure level is increasing from front to back and larger closing to the rear of the car with the maximum reaching to 90.4 dB, while the acoustic pressure level in the arc area of 12 m in diameter is higher than that of 10 m in diameter with the maximum gap of 15.1 dB.%利用FLUENT软件，对汽车的外场远点噪声进行仿真计算：通过稳态计算，得出汽车车身的表面声功率和声源分布情况，对车身的噪声源进行定性分析；通过瞬态计算，得到车身外场某点噪声的声压频谱图。仿真结果表明：汽车外场气动噪声源主要来自车身前脸、后视镜、前风窗玻璃、前轮；远场点的声压级由前向后有增大的趋势，并且靠近尾部区域声压级较大，最大达90．4dB，直径10m弧线上接收点的声压级值比直径12m的要高，其差值最大达15．1dB。