Scale effect analysis in aerodynamic performance of high-speed train

Calculation simulation was used to explore the scale effect in the aerodynamic performance of high-speed train under various working conditions (trains on open track, passing each other on open track, through a tunnel and passing each other in tunnel). Results show that, with decreasing model scale, the drag coefficient of the head and the whole train decreases, while the lift coefficient increases. For a single train passing through a tunnel and two trains passing each other in tunnel, the model scale does not change the surface pressure distribution properties along the train's longitudinal direction. When the train passing each other in full size, the pressure change amplitude of train surface is minimum. Under different working conditions, when the model scale is 1/20, the pressure change amplitude of wall surface is maxinmum; the increase of amplitude is up to 6%, compared with full-scale working condition. The experimental results can provide guidance for program design of data correction, wind tunnel test and moving model test when the test results of scaled models are extrapolated to the full-scale condition. © 2017, Zhejiang University Press. All right reserved.