侧风下峡谷桥隧连接段汽车的行驶特性

Cross-wind environment vehicle driving feature at canyon bridge and tunnel connection segment

为保障山区高速公路的运营安全,研究了在风环境下峡谷桥隧连接段车辆瞬态气动特性及其规律,借助Carsim软件建立车辆模型,并模拟峡谷桥隧连接处的路段特性,以西汉高速桥隧连接段的实测数据输入风速值和侧风角度等参数,来模拟不同风速及角度对车辆行驶的影响。首先,对运行仿真后得到的车辆纵向速度、侧向加速度、车辆气动三分力(气动阻力、侧向力、气动升力)、气动侧偏角等参数进行分析;其次,通过分析不同车速、风速、风向角的车辆气动力,探究其对行车稳定性的影响程度;最后,研究了车辆在侧风环境下安全稳定行驶的临界车速和临界风速。研究结果表明:车辆行驶在有侧风作用影响下的峡谷桥隧连接段时,车速由60 km/h提升至80 km/h,车辆气动阻力、侧向力及气动升力分别增加160%、53%及89%,并且在风速达80 km/h的冰雪路面下,伴随出现超过1 m的大偏移量侧滑,当经历西汉高速年最大风速31. 5 m/s(约113 km/h)时,车辆出现明显倾覆现象,对行车安全构成了一定的风险。

In order to solve the problem of highway traffic safety in the mountainous area,vehicle transient aerodynamic feature and its laws in bridge and tunnel connecting segment affected by the wind environment are studied.With the help of Carsim software,the vehicle model and the road model are built to simulate the feature of the vehicle and road in bridge and tunnel connecting segment.The measured varying wind speed of Xihan Expressway is input to simulate the average wind and fluctuating wind of the natural wind load,and the influence of wind angle on the vehicles is researched.Firstly,after simulation,the parameters,such as vehicle longitudinal speed,lateral acceleration,aerodynamic force(drag force,side force and lift force)and aerodynamic slip angle are analyzed.Then,the influences of the vehicle aerodynamic forces of different vehicle speeds,wind speeds and wind directions on the driving stability are analyzed.Finally,the critical vehicle speed and critical wind speed of safe and stable driving in the side wind environment are investigated.Research results show that,when the vehicle speed is increased from 60 km/h to 80 km/h,the drag force,side force and lift force are increased by 160%,53%and 89%respectively.Under the snow and ice surface with wind speed of 80 km/h,a large offset of more than one meter occurs.When the maximum wind speed of Xihan Expressway was 31.5 m/s(about 113 km/h),the vehicle will obviously overturn and it will be a risk to driving safety.