Analysis of high-speed train flow structures under crosswind
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The flow structures along the length of a High-Speed Train (HST) are experimentally investigated under simulated crosswind conditions. The experiment uses flow visualizations and velocity measurements in a wind tunnel on a HST model at various angles of yaw. Surface visualizations shows the development of a longitudinal vortex, originating at the nose which travels along the leeward side of the train. A hypothesis is presented and tested proposing flow structures may repeat when the Boundary layer (BL) on the roof of the HST reaches maximum development or is “pushed off”. A key motivation is to evaluate the validity of using shortened HST models in a wind tunnel to correctly represent full-length trains. Using this theory, a shortened train model appears unable to completely model full-scale HSTs at realistic yaw angles.
KeywordsAerodynamics Boundary layer Crosswind Flow structures Flow visualization High-speed train Wind tunnel
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