Influence of leading-edge angle of subgrade on aerodynamic loads of high-speed train in wind tunnel

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 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 boundary layer, the pressure acting on the lower part of the train head decreases, while on other location is 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 obviously when the thickness of boundary layer increasing. The experimental results obtained could serve as a calibration of aerodynamic forces for wind tunnel tests on high-speed trains.