Experimental investigation on the aerodynamics of tunnel-passing for high speed train with a moving model rig

When a high speed train enters a tunnel, a compressed wave occurs and propagates along the tunnel to the tunnel port, and transforms to be a micro pressure wave. Using the moving model rig experiment system, pressure waves and the micro pressure wave were measured in the double-track tunnel (60m in length) within the speed range of 200-350km/h. Firstly, the validity of experimental data was verified. Secondly, the reduction principle of the initial compression wave propagating in the tunnel and the relationship between the micro pressure wave and the train speed were drawn out. The effect of the streamlined nose shape on the micro pressure wave was studied at last. The experimental results show that in the speed ranges, the dimensionless values of the pressure wave and micro pressure wave are the same with different speeds. However, the relationship between the micro pressure wave and the streamlined nose length is only analyzed qualitatively, with quantitative relationship difficult to determine.