轿车侧窗风振特性的风洞试验研究

摘要

在分析了轿车风振产生机理的基础上,对目前工程上尚未解决的轿车侧窗风振问题进行了整车气动声学风洞试验.分析了侧窗风振噪声峰值声压级和频率随空间位置、风速大小、开口面积、偏航角和组合开窗的变化规律,对比了前窗和后窗的风振特性.结果表明:车内不同测试点的风振特征相似,即风振特性与车内空间位置无关.风振在某个特定风速下开始出现,并随着风速的升高逐渐增强,直到某个风速后又逐渐减弱,最后在另一个特定风速下消失.随着风速的增大,峰值声压级先增后减,而风振频率则一直升高.开口面积或偏航角增大时,峰值声压级和风振频率均上升.后侧窗风振问题较为严重,而前侧窗的风振则由于后视镜和A柱的存在,减弱很多.与只开一个窗相比,组合开窗可有效降低风振噪声.%On the basis of analysis on the generation mechanism of car wind buffeting, an aero-acoustic wind-tunnel test is conducted for car side-window buffeting so far unsettled in engineering. The changing law of the peak sound pressure level(SPL) and frequency of side-window buffeting with spatial location,wind speed,opening area,yaw angle and window-opening combination is analyzed and the wind buffeting characteristics of front and rear windows are compared.The results show that the characteristics of buffeting are almost the same in different locations in a car. Buffeting starts to appear at a certain wind speed and becomes stronger and stronger as wind speed goes up till a critical one,then it gradually weakens and finally disappears at another wind speed. As wind speed goes up, the peak SPL rises first and then falls, while the buffeting frequency keeps increasing. As window opening or yaw angle becomes larger,both buffeting frequency and peak SPL increase. The buffeting in rear window is much more serious than that of front window,which is weakened due to the effects of rearview mirror and A-pillar. In addition, compared with only one side window opening, the combination of different window openings can effectively reduce buffeting noise.