The influence of the leading-edge angle of subgrade on the aerodynamic loads of a high-speed train in a wind tunnel
Zeyun Yang, Gang Xu, Fan Wu, Lei Zhang, Jian Du, Dmitri Vainchtein
Abstract
Abstract The purpose of this study is to establish the correlation between the boundary layer over the subgrade and the aerodynamic loads acting on the train model in conventional wind tunnel tests. Firstly, flow characteristics around the subgrade with different leading-edge angles (15°, 30° and 45°) are investigated through the particle image velocimetry (PIV) experimental test method. Then, wind tunnel tests of the aerodynamic performance of a high-speed train are carried out. The results are compared with previous experimental data obtained by moving model tests. Results show that, due to the presence of a boundary layer, the pressure acting on the lower part of the train head decreases, while other locations are not significantly affected. This is the reason for the reduction of the aerodynamic drag and lift on the train. In addition, the reduction effects become more obvious when the thickness of the boundary layer increases. The experimental results obtained could serve as a calibration of aerodynamic forces for wind tunnel tests on high-speed trains.