不同类型风沙环境下高速列车气动特性分析

Analysis of Aerodynamic Characteristics of High-Speed Trains in Different Types of Sandy Environment

为研究风沙耦合作用对高速列车运行状态的影响,基于流体动力学理论建立高速列车空气动力学模型。采用三维、定常、不可压雷诺时均Navier-Stokes方程和标准κ-ε两方程湍流控制模型,模拟计算列车在平地、路堤和桥梁上行驶时的气动特性。沙粒采用欧拉-拉格朗日方法进行离散化处理,气流为连续化处理,这种处理方式与风沙自然状态非常吻合。研究结果表明:高速列车在有沙环境下的表面压力远大于无沙环境;列车头车受到的气动阻力最大,且沙粒对头车阻力的影响极为显著,较无沙环境头车阻力增加了(10~12)%;头车受到的倾覆力矩最大,尾车受到的倾覆力矩最小,方向与头车的受力相反;桥梁路况最大正压区相对较大,且列车两侧压力差最大,桥梁迎风侧凹槽处产生漩涡,背风侧产生双回流现象,致使气动性能最差。

It is to study the effect of wind-sand coupling on the running status of high-speed trains. It is based on the fluid dynamic theory that establishing the train aerodynamic model. The three-dimensional,steady,incompressible Reynolds time-averaged Navier-Stokes equation and the standard k-ε two-equation turbulence control model,which were used to simulate the aerodynamic performances and safety performance of trains in different types of wind-blown environment.The sand particles are discretized using the Euler-Lagrangian method,and the airflow is continuous.This treatment method is very consistent with the natural state of wind and sand. Results show that pressure distribution on the train in sandy environment is much greater than that of no-sand environment;The resistance of head train is the largest,and the impact of sand on the head train resistance is extremely significant,which is(10~12)% higher than the no-sand environment;The head train receives the maximum overturning moment,and the tail train receives the minimum overturning moment,and the direction is opposite to the force of the head train;The maximum positive pressure zone of the bridge road condition is relatively large,and the pressure difference between the two sides of the train is the largest.The vortex is generated at the groove on the windward side of the bridge,and the double leeward phenomenon occurs on the leeward side,resulting in the worst aerodynamic performance.