基于CFD的桥上车辆行车安全研究

Traffic Safety Research of Vehicle Running on Bridge Based on CFD

为了研究自然风荷载作用下车辆在大跨斜拉桥上的行车安全,以大客车、小汽车、半挂车为研究对象,采用CFD(Computational Fluid Dynamics)数值分析对风-车-桥耦合系统中车辆的气动特性进行分析。模拟不同风速、不同偏角风荷载作用下3种不同类型车辆在大跨斜拉桥上行驶时车辆气动力系数的变化规律,计算不同偏角自然风作用下各类型车辆以不同速度在桥上行驶时车辆发生倾覆及不同路面状况车辆发生侧滑的临界风速。对比车辆发生危险的临界风速表明,车辆以80~100km/h速度在大跨斜拉桥上行驶,当车辆在干路面上行驶时,大客车与半挂车车辆更容易发生倾覆,当路面的附着系数较小时则更容易发生侧滑,小汽车在桥面上行驶时相比较更容易发生侧滑。

For the sake of researching traffic safety while vehicle driving on the long-span cable-stayed bridge under natural wind,the aerodynamic characteristics of bus,car,semi-trailer which belong the wind-vehicle-bridge coupling system are respectively analyzed by Computational Fluid Dynamics numerical simulation method.The change rules of aerodynamic coefficients are analyzed while the three types of vehicle respectively driving on the long-span cable-stayed bridge under natural wind with different angle and speed.The critical wind speeds of vehicle overturning or sideslip on different road conditions are calculated while each type of vehicle driving on bridge with different speed under natural wind with variation angle.Comparing the minimum critical wind speeds can get that,bus and semi-trailer driving with 80~100 km/h speed on large span cable-stayed bridge are more likely to overturn when the pavement is dry,and more likely to sideslip when the pavement is wet,snow roads or ice roads,but car is easier to sideslip no matter driving on what kind of road conditions.Thereby,the traffic safety critical wind speeds above can provide a reference for traffic safety driving.