Comparison of partially averaged Navier-Stokes and large eddy simulation of the aerodynamic behaviors of a generic high-speed train

This paper investigates the influence of numerical methods and mesh resolution on the prediction accuracy of the aerodynamic behaviors of a 1/20 scaled generic high-speed train (HST) model. A thorough comparison is made between partially averaged Navier-Stokes (PANS), large eddy simulation (LES), and wind tunnel experiments, covering aerodynamic forces, surface pressure, velocity distribution, and Reynolds stress and turbulent kinetic energy in the wake region. The Reynolds number for both simulations and experiments is set to 4.75×105. The results show that the PANS approach accurately predicts flow characteristics observed in experiments and fine LES calculations, even with a low- resolution grid. PANS exhibits a distinct advantage over LES when grid resolutions are insufficient for resolving near-wall flow structures around the HST, both in open-air conditions and crosswind environments. Additionally, grid refinement improves the predictive accuracy of the HST's aerodynamic performance, particularly in the presence of small yaw angle.