Flow structure around trains under side wind conditions: a numerical study

Results of numerical investigations of high Reynolds number flows past a simplified train geometry under different yawing conditions are summarised. Variations of the incidence flow angle from parallel to normal with respect to the direction of the forward train motion resulted in the development of distinctively different flow patterns. To compute numerically the different flow structures, the three-dimensional Reynolds-averaged Navier–Stokes equations, combined with the k– ϵ turbulence model, were solved on a multi-block structured grid using a finite volume technique. The pressure–velocity fields were coupled using the SIMPLE algorithm. Despite the geometrical simplifications of the computed train configuration, the resulting flow fields show significant complexities.