后视镜造型对侧窗水相分布的影响

Influence of rearview mirror styling on water phase distribution on side windows

以乘用车后视镜为研究模型,采用格子玻尔兹曼方法,研究其尾部流场特性。将空气动力学与多相流理论相结合,在格子玻尔兹曼方法基础上应用拉格朗日方法,对雨天汽车行驶时后视镜对侧窗造成的水相分布进行研究,探究其污染机理,进而研究镜柱和镜罩两方面造型因素对侧窗的污染影响,其中镜柱包括长度和尺寸,镜罩包括迎风角度、内侧扩散角、前缘倒角和后缘离去角4个因素。结果表明:各因素对侧窗污染位置及污染比重有较大差异。增长镜柱、镜罩内侧扩散角改为0°、减小镜罩前缘倒角、后缘离去角改为0°皆会不同程度降低污染水平,镜柱尺寸和镜罩迎风角对侧窗影响较为复杂,但也可得到较小水平污染结果,各因素对侧窗污染影响并非独立作用。

Based on the rearview mirrors of sedans,the Lattice Boltzmann method is used to study the flow field characteristics of the rearview mirrors. Combining aerodynamics with multiphase flow theory,the Lagrangian method is applied on the basis of the lattice Boltzmann method to study the water phase distribution on side windows caused by the rearview mirror on rainy days,and to investigate the pollution mechanism. Then the pollution effects of the mirror column and the mirror cover on the side window are studied. The mirror column factors include the length and size,and the mirror cover factors include the windward angle,the inside diffuser angle,the leading edge chamfer angle and the rear departure angle. The Results show that these factors have significant different influences on pollution location and pollution degree of the side windows. Increasing the column length,changing the inside diffuser angle of the cover to0°,reducing the leading edge chamfer angle of the front cover and changing the rear departure angle to 0°will reduce the pollution level. The influence of the size of the mirror column and the windward angle of the mirror cover on the side window is complicated,but a lower pollution degree can also be obtained. The influence of each factor on the side window pollution is not independent.