Numerical study of the influence of dome shape on the unsteady aerodynamic performance of a high-speed train's pantograph subjected to crosswind

This study aims to investigate the unsteady aerodynamic performance of a high-speed train's pantograph with respect to two different dome shapes and without dome under a 20° yaw angle using a delayed detached eddy simulation method. Further, the influence of the dome shape on the simulation results is determined. The accuracy of the numerical method was validated by comparing a few of the numerical results with the wind tunnel test results, and high consistency was observed. An analysis of aerodynamic forces and flow structures around the pantograph was performed. The dome had significant influence on velocity field distribution surrounding the pantograph, particularly in the wake of flow region. Compared with the case where the dome was absent, vortex intensity around the pantograph increased after installing the dome. The existence of the bathtub-type dome resulted in greater flow field disturbance and vortex strength than the baffle-type dome. Moreover, the dome considerably affected time-averaged aerodynamic coefficients and their fluctuations, especially the bathtub-type dome. Additionally, the power spectral density of the unsteady aerodynamic coefficient of each pantograph component exhibited significant peaks and typical broadband distribution characteristics.