地板缝隙对高速列车模型风洞试验结果的影响

Influence of Floor Gap on Wind Tunnel Test Results for High-Speed Train Model

为了研究高速列车风洞试验的固定地板中心转盘周围缝隙对列车模型气动特性试验结果的影响,对1∶20的一节半车编组高速列车模型,采用固定地板模拟了间隙平地,获得了如下结论:地板中心转盘与周围地板之间有8 mm的缝隙时,缝隙并未明显引起该处地板上下表面形成气流“串流”的情况;有无缝隙对头车气动阻力,头车典型纵向中心剖面压力等影响较小,有缝隙时的头车升力有增大的趋势(绝对值减小)。缝隙对地板中心表面附面层厚度的影响量约为1.8%,有缝隙的地板表面附面层厚度有减小的趋势。研究结果为采用固定地板模拟地面条件的高速列车风洞试验提供了参考,也可为固定地板转盘表面的结构缝隙尺寸设计提供参考。

In order to study the influence of the gap around the center turntable of fixed floor on the test results of the aerodynamic characteristics of the high speed train model in the wind tunnel test, for the 1:20 scaled high speed train mode of lone and half car formation, the state of gap-ground is simulated with the fixed floor, and the influence of the gap around the floor turntable on the aerodynamic characteristics of the train model is studied. The following conclusions are obtained: when there is a 8 mm gap between the central turntable and its surrounding floor, the gap does not obviously cause the exchange of air flow on the upper and lower surface of the floor. The influence of gap is little on the aerodynamic drag of the head car, the pressure of the longitudinal center section of the head car etc, and the air velocity profile and velocity values of the floor central surface. The lift of the head car tends to increase(the absolute values decrease) with the gap. The influence of the gap on the boundary layer thickness of the floor surface is about 1.8%, and the thickness tends to decrease with the gap. The research results provide a reference for the wind tunnel test of the high speed train by using the fixed floor to simulate the ground conditions, as well as the design of the structural gap size on the surface of the fixed floor turntable.