侧风下队列行驶车辆的气动特性研究

发布时间：2018-03-08 15:38

本文选题：队列车辆　切入点：数值模拟　出处：《吉林大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国道路和汽车工业的发展,汽车的行驶速度不断加快,汽车的数量逐渐增多,汽车的行驶条件变得越来越复杂。在遭遇侧风时,汽车高速转弯,汽车过隧道,两车相会,这些复杂情况将导致汽车之间产生气流,会对汽车的行驶稳定性和驾驶安全性产生重大的影响,严重时将导致交通事故。在山道上、高速公路上,大客车和小轿车尾随的情况更是经常发生。另外,对于大型客车,如果在山路,高速公路上遇到较强的侧风,会极大地降低大客车的行驶安全性和侧风稳定性。目前,国内对汽车空气动力学研究主要集中于单车方面,对队列行驶车辆的流场分析较少。本文将采用数值模拟仿真以及风洞实验的方法,通过改变队列行驶车辆的间距以及侧风角度,重点研究间距、侧风角度的变化对于队列车辆气动特性和侧风稳定性的影响规律,同时分析大客车尾流场压力系数的变化情况,探索其尾流结构的变化机理,为瞬态数值模拟仿真以及风洞试验奠定坚实的基础,对未来智能交通系统自动驾驶以及多车自动编队行驶具有基础研究的意义。本文主要研究侧风下队列行驶车辆的稳定性,从侧风角度和队列车辆行驶间距两方面对大客车和厢式车进行研究,本文的研究主要有以下四个方面:一、通过数值模拟仿真以及风洞试验研究了大客车单独行驶时大客车外流场的空气动力特性,分析了流场的变化趋势,验证了仿真方案的正确性。二、通过进行队列车辆在几种不同横摆角下(β=0°、5°、10°、15°)的风洞试验以及数值模拟仿真,着重关注了侧风条件下大客车的气动阻力、气动侧向力以及气动升力的变化,验证了侧风下队列行驶车辆数值模拟仿真方案的正确性。三、通过对比侧风作用下车身表面压力分布,分别对其气动特性和外流场进行分析,分析了侧风下队列行驶车辆的周围流场变化,比较侧风对队列车辆气动特性的影响。四、进行PSI压力测试试验,获取侧风下队列车辆在三种不同间距(0.6m、1.2m、1.8m)的风洞试验数据,进行大客车尾流场的气动特性研究;重点研究尾流场压力系数的变化,探索尾流结构变化机理,分析了间距以及侧风强度对大客车尾流结构的影响。
[Abstract]:With the development of road and automobile industry in our country, the driving speed of automobile is speeding up, the number of cars is increasing, and the driving conditions of automobile are becoming more and more complicated. In the face of crosswind, the car turns at high speed, the car passes through the tunnel, and the two cars meet each other. These complications will lead to airflow between cars, will have a significant impact on vehicle stability and driving safety, and in serious cases will lead to traffic accidents. The trailing situation of buses and cars is more frequent. In addition, for large passenger cars, if strong crosswinds are encountered on mountain roads and expressways, the driving safety and crosswind stability of buses will be greatly reduced. The research of automobile aerodynamics in China is mainly focused on the single vehicle, but the analysis of the flow field of the queued vehicle is less. The method of numerical simulation and wind tunnel experiment will be adopted in this paper. By changing the distance and the crosswind angle of the vehicles traveling in the queue, the influence of the distance and the crosswind angle on the aerodynamic characteristics and the crosswind stability of the queue vehicles is studied, and the variation of the pressure coefficient of the wake flow field of the bus is analyzed at the same time. The change mechanism of its wake structure is explored to lay a solid foundation for transient numerical simulation and wind tunnel test. It is of fundamental significance to the future intelligent transportation system (its) autonomous driving and multi-vehicle automatic formation driving. In this paper, the stability of the vehicles in queue under crosswind is studied. In this paper, there are four main aspects in the study of bus and van from the angle of cross-wind and the distance between the vehicles in the queue. The main contents are as follows: first, Through numerical simulation and wind tunnel test, the aerodynamic characteristics of the external flow field of a bus traveling alone are studied. The variation trend of the flow field is analyzed, and the correctness of the simulation scheme is verified. Through wind tunnel test and numerical simulation of queue vehicles at different yaw angles (尾 0 掳/ 5 掳/ 10 掳/ 15 掳), the variation of aerodynamic resistance, aerodynamic lateral force and aerodynamic lift of passenger cars under crosswind conditions are focused on. The correctness of the numerical simulation scheme of queue driving vehicles under crosswind is verified. Thirdly, by comparing the surface pressure distribution of the body under cross-wind, the aerodynamic characteristics and the flow field of the vehicle are analyzed respectively. In this paper, the variation of flow field around the vehicles traveling in queue under crosswind is analyzed, and the influence of crosswind on aerodynamic characteristics of queue vehicles is compared. Fourthly, PSI pressure test is carried out to obtain wind tunnel test data of queue vehicles under cross wind at three different distances of 0.6 mv 1.2 m-1 / 1.8 m). The aerodynamic characteristics of the wake field of a bus are studied, the variation of the pressure coefficient of the wake field is studied, the mechanism of the wake structure change is explored, and the influence of the distance and the cross-wind intensity on the wake structure of the bus is analyzed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U461.1

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