乘用车风噪声模拟研究

对某乘用车风噪声进行了模拟研究.首先,采用大涡模拟模型（LES）计算了乘用车的瞬态外流场,然后,应用Lighthill-Curle声学模拟理论,以后视镜及A柱区域为噪声源,预测了车外场点的噪声特性,模拟值与测量值在高频范围内比较符合.根据流场和声学模拟结果,分析了后视镜的声学缺陷.通过取消原后视镜上的凹槽,增加后视镜与A柱之间的连接距离,减小后视镜迎风面积和构形等手段,对后视镜的声学敏感区域进行了修改.最后,对修改后的模型进行了噪声测量,试验结果显示,模型修改后风噪声有显著降低.

Wind noise simulation of passenger car

The wind and tyre-road noises are the main noise source under the middle and high velocity.Large eddy simulation(LES) was applied to calculate the transient external flow field,then the Lighthill-Curle acoustic theory was used to predict the wind noise level.For example,the rearview mirror and a front pillar of some passenger car were sellected as the noise source and the noise radiated form them was simulated.The computed results agreeded well with the experimental data.The acoustic defects were analyzed according to the fluid and acoustic simulation results.The mirror was improved by the removal of the groove,increasing the connecting distance between the mirror and the front pillar,decreasing the area of the windward side and so on.At last,the wind noise of the improved passenger car was measured.The experiment showed that the noise level was greatly decreased.