Abstract: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 the comfort of passengers, 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 at 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 software. Then the fluent fluid simulation was used to simulate the train with steady-state running speed of 300 km/h based on the standard model to calculate the air resistance. Finally, the train with good aerodynamic performance is simulated by using broad band noise. The results show that the convex hull array structure with a pitch of 460 mm, a radius of 40mm and a height of 10 mm around the wind screen has a positive effect on reducing the aerodynamic drag. The resistance value is 3 715 N, 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, with the maximum noise reduction rate of 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 some positions.