Correlation tests on train aerodynamics between multiple wind tunnels

Abstract

Wind tunnel tests on rail vehicles, especially the crosswind evaluation, are often used for the determination of critical wind characteristics. To increase the reliability of the wind tunnels for these requirements, correlation data between various wind tunnels is necessary. Along those lines, a wind tunnel campaign on a 1/20th high-speed train was conducted at three separated facilities, including the study of two floor configurations within the same wind tunnel. A symmetry check was made by monitoring pressure signals at both sides of the vehicle, and the load coefficients that fall within negative and positive yaw angles. The results show good consistency with aerodynamic load coefficients measured at separated wind tunnels. The standard deviation of CMx,lee increases with the yaw angle exponentially. Pressure taps for geometric transitions and suction peaks tend to have a larger level of symmetry discrepancies than other taps. Pressure distributions for longitudinal centerline and loops in all facilities have a similar trend, while the dispersion degree slightly differs in various regions. These differences are partly explainable by the experimental settings, i.e., the boundary layer development above the floor, the offset installation of the model, and the floor configurations. Therefore, special attention is suggested to be paid to the floor configurations and boundary layers above the floor when performing related experimental works.