Wind-tunnel Test Model Design And Numerical Simulation Analysis Of CRH₂Train And Simply Supported Box Grider Under Crosswind

Thestudy on laws of train and bridge system aerodynamic characteristics is the foundation of study on security of high speed train on bridge. The research in this paper is one of the main content of the National Natural Science Foundation Project "Wind tunnel experiments study on the aerodynamic characteristics of vehicle-bridge system for high-speed railway and overturning resistance of train under strong wind environment (NO.51178471)", CRH2Train and typical simple supported girder bridge of32m at Beijing-Shanghai high-speed railway are studied by using CFD numerical simulator Fluent to do research on mutual aerodynamic characteristics between high speed train and bridge and capsizing stability of train. And moving vehicle model is designed according to the conditions of wind tunnel laboratory in CSU to study aerodynamic characteristics of moving train and bridge under different situations, Following is details:1.A set of1:25wind tunnel test systems of moving vehicles are developed. Windspeed, trainspeed, relative location and crossing situation of trains can change easily using this system. In this way, various test conditions can be realized. Both pressure testing methods and forces testing methods are schemed to be adopt in the research for comparson. At present, pressure testing is started and Wireless power measurement and control system are being developed.2.As the pier-space of simple supported girder bridge is small,deep study is made on mutual effect between train, bridge and pier. The aerodynamics characteristics of vehicle and bridge are analyzed when trains run on the bridge. The aerodynamics characteristics of each other are calculated at different wind speeds, wind deflection angles, turbulence intensity or crossing train positions at lengthwise direction to develop the changing regularity. Specific reasons are given to the change of aerodynamics coefficients of vehicles and bridges according to pressure distribution and changing regularity of flow chart of flow field around train and bridge. Comparison of the changing regularity of aerodynamics coefficients of different trains of set CRH under various wind deflection angels are made.3.The thesis makes an analysis of the impact of wind barrier’s height and the ventilstion rate and discuss the changing regularity of the train areodynamics power in situation of different wind speed and different train speed considing resultant wind, then select the initial proper wind barrier.4.An specific analysis of train Stability against capsizing performa-nce in situation of having wind barrier or not is made, forming the basic principle of choosing wind barrier.