基于凸包非光滑表面的高速列车减阻技术

为减少高速列车在运行中的空气阻力,提高列车运行效率、节约能耗,提出凸包非光滑表面减阻技术应用于高速列车领域.文中以CRH3型高速列车为研究对象,通过在车体的头部和尾部加设凸包来控制湍流特性,以达到减阻效果.首先利用PRO/Engineer建立非光滑表面CRH3型头车+中间车+尾车的简化模型,将模型导入ICEM CFD软...

Drag Reduction Technology for High-speed Train Based on Non-smooth Surface of Convex Hull

In order to reduce the air resistance of high-speed trains in operation,improve the efficiency of train operation and save energy,this paper puts forward the application of convex hull non-smooth surface drag reduction technology in high-speed trains.Taking CRH3 as the re?search object,and controls the turbulence characteristics by adding convex hulls on the head and tail of the car body to achieve the drag reduc?tion effect.Firstly,a simplified model of non-smooth surface CRH3 which include head vehicle,intermediate vehicle,tail vehicle were estab?lished by using PRO/Engineer.Then the model was imported into ICEM CFD software and different mesh areas are divided according to the need of calculation accuracy to obtain a higher quality unstructured grid.After that,the turbulence model in FLUENT software was used to simulate the train with steady-state running speed of 300 km/h to calculate the air resistance of the train and compare the influence of the ar?ray distance,radius and height of the convex hull on the drag reduction performance.The influence of the non-smooth surface of the convex hull on the differential pressure of the high-speed train is reflected from the pressure diagram of the head vehicle,tail vehicle and the nearby velocity vector diagram.Effect of non-smooth surface of convex hull on viscosity resistance change of high speed train was explained from perspective of the turbulence intensity and the turbulence kinetic energy.The simulation results shows that the aerodynamic drag of the train decreases with the increase of the distance of the convex hull array,decreases with the decrease of the convex hull radius,and decreases with the decrease of the convex hull height.The train has the best drag reduction effect when the radius is 40 mm,the array distance is 460 mm and the height of the convex hull is 10 mm.Compared with the smooth surface train,when the front vehicle is provided with a convex hull and the tail vehicle is not added,the head car resistance is 1239 N,the head vehicle drag reduction rate is 10.67%,the total resistance is 3591 N,and the total drag reduction rate is 3.80%.Obviously,the turbulence characteristics of the boundary layer can be changed to reduce the aerodynamic drag of the train by adding a convex hull on the head vehicle.It is expected that the research in this paper will provide a refer?ence for the study of the drag reduction method for high-speed trains.