Research On Aerodynamic Characteristics Of Vehicle Platoon Within Crosswind

With the development of China’s road and the automotive industry, the speed of the vehicle is speeding up. The number of vehicle is increasing, the driving condition of the vehicle is becoming more and more complex. when facing the crosswind, vehicle turns with high speed, vehicle travels over tunnel, vehicles meet directly. These complex conditions will lead to the production of airflow between the vehicles, and will have a significant impact on the aerodynamic stability and safety of the car, or even will lead to serious traffic accidents. On the road or highway, the following situation of bus and car has often happened. In addition, for large passenger cars, If encountering strong crosswind on the highway or on the road, it will greatly reduce the safety of vehicle and also has a great influence on crosswind stability.At present, the domestic research on automotive aerodynamics mainly focuses on the single bus, the research on the flow field analysis of the queue vehicles is less than others. The method of numerical simulation is adopted in this paper. By changing the distance of queue vehicles and crosswind angle. Focusing on the influence of the crosswind on dynamic characteristics of the queue vehicle. At the same time we can summarize the effect on the aerodynamic characteristics and stability of queue vehicle, under the condition of different distance, different yaw angles. At the same time, the change of the pressure coefficient of the rear flow field of the bus is analyzed, and the mechanism of the change of the wake structure is explored.Laying a solid foundation for the transient CFD simulation and wind tunnel experiment, Providing guidance and advice on aerodynamics for the aerodynamic characteristics of the vehicle in the future.This paper do research on crosswind stability of the queue vehicle, and study it from crosswind yaw angles and distance between the queue vehicle. The research of this paper mainly has the following four aspects:First, Through numerical simulation and wind tunnel test, doing research on the aerodynamic characteristics of the single bus flow field, the changing trend of the air flow is analyzed, and the correctness of the simulation scheme is verified.Second, through crosswind wind tunnel experiment and numerical simulation of the queue vehicles with four different yaw angle(β= 0 degrees, 5 degrees, 10 degrees, 15 degrees), we focus on the change of vehicle aerodynamic drag force, lateral force and lift force in the crosswind condition, and also we can verify the correctness of simulation scheme under the condition of the queue vehicles in the crosswind.Third, through the contrast of the body surface pressure under the crosswind, respectively analysis dynamic characteristic and flow field, analysis aerodynamic changes of the queue vehicle under the crosswind, and compare effects of crosswind on the dynamic characteristics of vehicle queue.Fourth, PSI experiment were performed, we get the wind tunnel test data under the condition three different distances(0.6m, 1.2m, 1.8m) of the queue vehicle under the crosswind. Then doing research on the aerodynamic characteristics of bus tail flow field. The variation of pressure coefficient in Tail flow field is mainly studied. Exploring the change mechanism of tail flow structure. Analysis the effect of driving distance and crosswind intensity on the wake structure.