School of Mechanical and Vehicle Engineering,East China Jiaotong University
In order to reduce the aerodynamic drag and noise of high-speed trains in operation, improve the train operation efficiency, save energy consumption and improve passenger comfort, the convex hull non-smooth surface drag reduction technology is applied to the field of high-speed trains in this paper. Taking the CRH3 high-speed train as the research object, the turbulence characteristics are controlled by adding convex hulls on the head and tail of the car body to achieve the effects of drag reduction and noise reduction. Firstly, the simplified model of non-smooth surface CRH3 high-speed train was built by PRO/Engineer. The model was divided into unstructured grids by ICEM CFD. Then the Fluent fluid simulation was used to simulate the train with steady-state running speed of 300km/h based on the standard model. Calculate the air resistance. Finally, use broadband noise to simulate the external surface noise of the train with good aerodynamic performance. The results show that the convex hull array structure with a pitch of 460mm, a radius of 40mm and a height of 10mm is arranged around the front windshield to have a positive effect on reducing the aerodynamic drag. The resistance value is 3715N, and the drag reduction rate is 1.77%. The parameter convex hull is non-smooth and has a general noise reduction effect on the upper edge of the train skirt. The maximum noise reduction rate is 1.72%, and noise is added to the nose and the top of the car. It can be seen that by adding a convex hull in the head car, the turbulence characteristics of the boundary layer can be changed to reduce the aerodynamic drag of the train and reduce the aerodynamic noise at a partial position. It is expected that the research in this paper will provide a reference for the study of drag reduction and noise reduction methods for high-speed trains.