Wind tunnel testing on a train model subjected to crosswinds with different windbreak walls

Crosswind stability of high-speed trains has been a prominent research topic for several decades, primarily motivated by the frequent rail-related accidents under strong crosswinds. In this study, the influence of different windbreak walls on train aerodynamic properties whilst subjected to crosswinds was assessed. The experimental campaign measured surface pressures on a stationary 1:25 model-scale of Class 390 Pendolino train under varying wind incidence angles with different windbreak walls inside a wind tunnel. For the first time, the work considers transition regions in windbreak walls, where transition regions refer to random geometrical changes in the distance between the train and the windbreak wall. Differences in pressure distribution on the train surface with and without different windbreak walls are evident. Forces on the train are calculated using the mean pressure coefficients. Overall, at a yaw angle of 90 degrees, the tallest windbreak wall usually provided lowest mean pressure distribution on the surface of the model train due to the shielding effects; while the windbreak wall with a transition region of 90 degrees usually produced the highest mean pressure distribution, comparatively. At a yaw angle of 30 degrees, the results from windbreak walls with transition regions were relatively uniform indicating a smooth pressure distribution.