Wind Tunnel Test Study for the Influence of Reynolds Number on the Aerodynamic Performance of High-speed Trains

The low temperature variable Reynolds number wind tunnel test for a high-speed train model (EMU) with a leading car and half of middle car is done to study the aerodynamic performance of high-speed trains in the Reynolds number range between 106 and 107, and the conformity test is performed with a scaled ICE3 model. The test results show that the drag of the leading car decreases almost monotonically with increasing yaw angle, while the side and lift force increases with increasing yaw angle. The Cmxlee, which is the most important parameter with respect to cross-wind stability, also increases with increasing yaw angle. The drag force coefficient (Cfx) of the leading car decreases with higher Reynolds number for yaw angles of 0°. The Cfx drops about 0.03 when the Reynolds number is raised from 1 million to 10 million. The lift force coefficient decreases with higher Reynolds numbers.