横风下流线箱型桥-轨道交通车辆气动干扰风洞实验研究

Wind tunnel tests for aerodynamic interference between streamline type box bridges and rail vehicles under cross wind

轨道交通车辆与桥梁间存在显著的气动干扰,但现有研究大多以流线型高铁车辆和钝体外形的简支梁桥为研究对象,且往往重点关注桥梁对车辆气动力大小的影响。以某流线箱型轨道专用桥和钝体外形的轨道交通车辆为背景,首先通过刚性节段模型测力试验,利用开发的车-桥系统气动力同步分离装置对不同风攻角、车桥组合方式下车辆和桥梁各自的气动力进行测试,分析横风下车桥间气动干扰对车辆、主梁和车桥系统所受总体气动力的影响规律;然后结合烟线法获得的车桥系统绕流场显示结果,揭示车桥间气动干扰机理。研究成果可为以后典型车桥组合工况下车、桥气动力经验公式的提出奠定基础,以及深入认识车桥间气动干扰机理提供参考。

Existing studies showed that there is a significant aerodynamic interference between rail vehicles and bridges, however, most existing studies focus on streamline type high-speed rail vehicles and simply supported beam bridges with a blunt body shape, and the influence of bridge on aerodynamic forces of vehicle. Here, the aerodynamic interference between a streamline type box bridge and a rail vehicle with a blunt body shape was studied. The aerodynamic forces of the vehicle and the bridge for different combination cases and wind attack angles were measured in the wind tunnel laboratory of Central South University with a rigid section model force-measuring test, and a test platform was developed to ensure that the aerodynamic forces of the vehicle and the bridge can be measured synchronously. According to test results, the influences of aerodynamic interference between the vehicle and the bridge on the aerodynamic forces of the vehicle, the bridge and the vehicle-bridge system were analyzed. Furthermore, the aerodynamic interference mechanism was revealed according to the flow field visualization results which were obtained with the smoke-wire technique. The results laid a foundation for deriving empirical formulas to calculate the aerodynamic forces of vehicles and bridges considering their dynamic interference, and provided a reference for deeply understanding the aerodynamic interference mechanism between vehicles and bridges.