汽车天窗耦合风振噪声规律及机理研究

Research on Regularity and Mechanism of Vehicle Coupling Sunroof Buffeting Noise

摘要: 风振噪声是汽车行驶过程中车窗开启时普遍存在的问题，本文利用LBM-LES方法对天窗风振噪声特性进行研究。计算分析了不同来流速度、不同天窗开度以及天窗与侧窗耦合工况下的天窗风振噪声，结果表明：发生Helmholtz共振的来流速度下风振现象最明显；风振噪声随天窗开度大小的增大而增大；风振噪声产生机理：天窗开口处剪切层内涡的周期性脱落导致乘员室腔体内压力呈周期性脉动；左后侧窗–天窗完全开启工况下无“通风效应”；由于流体的直接作用，在垂直于开启的车窗方向上，风振噪声强度从窗口向内依次递增。

Abstract: Wind buffeting noise as popular problem exists in the vehicle driving process when windows opened. In this paper, the characteristics of sunroof buffeting noise are studied by LBM-LES simu-lation. The sunroof buffeting noise under conditions of different speeds, different opening size and different combined opening pattern of sunroof and side-window is simulated and analyzed. The results demonstrate that the most obvious phenomenon of sunroof buffeting occurs at the speed which Helmholtz resonance arises. The buffeting noise increases with the increase of sunroof opening size. The mechanism of sunroof buffeting is that the periodic pressure fluctuation of the cabin is caused by periodic vortex shedding in the shear layer of sunroof opening. The “aeration effect” does not exist when the left-front side window and sunroof are opened. Because of the direct action of fluid, in the direction perpendicular to the open window, the buffeting noise increases from the window to the inside.