基于格子玻尔兹曼方法的侧窗水相分析与控制

Analysis and control of water phase of side window based on Boltzmann method

侧窗雨水污染会损害侧窗的清晰度,进而影响汽车的安全驾驶.针对汽车雨天行驶时侧窗水污染问题,将空气动力学与多相流理论结合,采用格子玻尔兹曼方法求解汽车瞬时外流场,拉格朗日方法求解液滴运动,获得液滴运动轨迹和侧窗区域水相分布情况.分析得到侧窗区域水污染的影响因素及产生机理,在此基础上对A柱型面进行改型,对比不同改型方案的侧窗区域水相分布情况以及污染面积.研究结果表明,在4种A柱方案中,方案2侧窗视野最佳,水相覆盖率为38.2%,较basic模型降低了19.2%.

Side window clarity and its effect on side mirror visibility plays a major role in safe driving. In view of the problem of side window water pollution when a car is driving in rainy days, combined the aerodynamics and multiphase theory, the Boltzmann method and Lagrangian method are used to solve the transient external flow field and the droplet movement in this paper. Trajectory of the droplet and distribution of the water phase in the side window area are given, the mechanism of water pollution in the side window area is analyzed and the A-column surface is modified. Four different schemes are established, the effects of different schemes on the water film distribution in the side window area are compared and the image processing technology is used to quantify the pollution area. The results show that the four schemes all play a role in reducing water pollution in the side window area. The side window of scheme 2 is the best, the water film coverage is 38.2%, which is decreased by 19.2% compared with the basic model.