Experimental and Numerical Study on the Aerodynamic Performance of High-Speed Trains

Abstract

Moving high-speed train model tests and CFD computations are used in this paper to explore the influence of Reynolds number on the aerodynamic performance of high-speed trains and on the pressure wave created when two trains passing each other. The effect of the test model scale for two trains passing each other on an open track, running through a tunnel and passing each other in a tunnel are studied by numerical simulations. The results of the moving model tests show that the pressure wave amplitudes of passing trains increase with the vehicle speed, and this amplitude coefficient decreases with the vehicle speed (that is, the Reynolds number increases). From the numerical calculation it is shown that the effect of scaling does not change the trend in surface pressure distribution along train's longitudinal direction. When two trains pass each other at an equal speed, the pressure changes in the head area are largest, followed by the tail area. The pressure changes in other areas are relatively small. The results for the 1:8 model and the 1:1 model are very close; considering the differences in computational efficiency and accuracy, the 1:8 model can be used for calculations. Using these two complementary methods, the results of the study can be used to design full scale high-speed trains, and to provide guidance for moving model tests and numerical simulation.