Influence Of Spoilers On The Aerodynamic Performance Of The High-speed Train

Based on spalart-allmaras equations model, the influences of spoilers with different ways at the rear of the train to the aerodynamic performance of the high-speed train was researched. research results are as follows:To the high-speed train without spoilers,the aerodynamic drag of the head car is less than that of the end car, and the aerodynamic lift of the former is more than that of the latter; the two trailing vortexs distribute with train longitudinal cross-section as the separatrix, and they are of opposite directions. Because of turbulence properties, their intensitities are unequal,furthermore, with the distance away from the end car becoming farther, the intensity of the positive and negative pressure center decline,the air velocity of the vortexs declines and their distance largen.Adding a horizontal spoiler to the high-speed end car, the aerodynamic drag of the end car increases, and the lift declines; comparing to the high-speed train without spoilers, the positive pressure center of the end car moves up to the top of the horizontal spoiler, and its intensity strengthens, but its area becomes smaller, furthermore,a negative area appears at the bottom of the spoiler. Increasing the horizontal spoiler height, the aerodynamic drag of the end car increases, and the lift declines, and the positive pressure intensity above the spoiler strengthen;Adding a vertical spoiler to the high-speed end car, the aerodynamic drag of the end car increases, and the lift declines; comparing to the high-speed train with a horizontal spoiler, the area of the positive pressure in the end car surface is larger, and the intensity is weaker; Increasing the vertical spoiler height, the aerodynamic drag of the end car increases, and the lift declines, and the positive pressure intensity above the spoiler strengthen weaker than the train with a horizontal spoiler. Adding a sideway spoiler to the high-speed end car, the aerodynamic drag and the lift of the end car both declines; comparing to the high-speed train with a horizontal spoiler or vertical spoiler, the area of the positive pressure in the end car is much larger, and the intensity is stronger.To sum up, on one hand the installation of a sideway spoiler on the rear reduces aerodynamic drag of end car, which makes a contribution to lower the energy consumption, on the other hand, it reduces aerodynamic lift force to ensure running safety.