队列行驶三辆汽车外流场的数值模拟

以智能车辆的MIRA简化模型作为研究对象,在自动控制的前提下,采用移动地面边界条件,对单车和队列行驶状态下的汽车外流场进行了数值模拟研究.分别获得了单车和各种行驶工况下的三辆汽车对称面的压力分布,队列行驶三辆汽车的压力分布与单车的压力分布相似,但是后两车前部的正压区明显减弱.对于等间距和不等间距2种行驶情况,改变车辆之间的距离来模拟多种状态.气动阻力的对比分析说明:队列行驶的三辆汽车,后两车的气动阻力都低于前车的气动阻力,而且平均气动阻力与单车相比均有了一定程度的降低.通过间距的改变分别进行数值模拟,获得了间距对前后行驶三辆汽车气动阻力影响的规律,为以后队列行驶的深入研究奠定了基础.

Numerical Simulation of Flow Field around Three-Car Platoon

Based on auto-control,the MIRA simplified model was used as the object of Intelligent Vehicle System research,and the flow field around single car and three-car platoon were numerically simulated respectively,while the ground effect was simulated by the moving wall boundary condition.The pressure distributions in symmetry section are shown.Comparing with the distribution of a single car,the situations are similar,but the positive pressure area of the two back cars' front part is evidently weakened.There are two types of positions,the same space and different space.The analysis of aerodynamics resistances shows that the two back cars' resistances are smaller than the leading car's resistance and the average resistance falls a little contrasting with the single car's resistance.The numerical simulations of flow field around three-car platoon were carried out by changing the distance of cars.The rule of aerodynamics resistances of three cars platoon influenced by space is found.It establishes the base for the latter research.