An experimental study of aerodynamic drag on high-speed train

A series of wind tunnel tests were conducted for Korean high-speed train mo del with various shape components to assess the contributions to aerodynami c drag. In order to elucidate the ground effects, two different wind tunnel s, one with a moving ground system and the other with a fixed ground, were used for the same model and the results of both were compared and analyzed in detail. The results show that a suitable ground simulation is necessary for the test of a train model with many cars and detailed underbody. But th e relative difference of the drag coefficients for the modifications of sha pe components can be measured by a fixed ground test with high accuracy and low cost. The effects of the nose shape, the inter-car gap and the bogie-f airing on total drag were discussed and some ideas were prosed to decrease the aerodynamic resistance of high speed train.