Analysis of High Speed Train Flow Structures Under Crosswind

The flow structures along the length of a High-Speed Train (HST) under crosswind are investigated in a wind tunnel, through flow visualisations and velocity measurements at various angles of yaw. Surface visualisations show the development of a streamwise vortex originating at the nose that travels longitudinally along the length of the train. In addition, the hypothesis that flow structures repeat when the boundary layer (BL) on the roof of the HST model is pushed off is tested, with a view to analysing the effectiveness of using shortened HST models to accurately represent full-length trains in a wind tunnel. It would appear that using a shortened train model cannot completely model full-scale HSTs at realistic yaw angles using this theory.