车体侧滚对列车气动性能和运行稳定性的影响

Effect of train body roll on aerodynamic performance and moving stability of high-speed train

为探明横风作用下车体侧滚对列车气动性能和运行稳定性的影响,采用三维、定常、不可压缩雷诺时均方程和k-ε双方程湍流模型,对CRH5G动车组进行仿真计算。研究结果表明:当侧滚角从0°增加到2.5°时,车底部迎风侧负压减小,绝对值最大相差532 Pa,车顶迎风侧负压增大,绝对值最大相差579 Pa,车底压力变化的区域更大,车顶和车底背风侧的压力变化都不大;头车后部车底负压减小,绝对值最大相差470 Pa;气动力方面,列车升力增大,头车升力变化最为明显,从0.15 k N增加到16.6 k N;头车的点头力矩提升了20%,尾车的点头力矩下降了7%;进一步的车辆动力学仿真计算结果表明:车体侧滚引起的气动载荷变化对列车脱轨系数、倾覆系数的影响很小。因而在研究横风作用下的列车运行稳定性时,一般可不考虑车体侧滚对气动性能的影响。

In order to figure the aerodynamic performance and moving stability of high-speed train under crosswind in different angles of roll out, 3 D steady uncompressible Reynolds-averaged N-S equation and k-ε double-equation turbulent model were used to simulate the aerodynamic performance of CRH5 G. The results show that when the angle of roll increases from 0° to 2.5°, the pressure at the bottom of the train's windward part increases, and the biggest gap is 532 Pa; while the pressure at the top of the train's windward part decreases, and the biggest gap is 579 Pa. The pressure of the train's leeward part keep unchanged. The lift force increases, and the head train's lift force varies from 0.15 k N to 16.6 k N, which is the biggest lift force change unit. The nodding moment of head train increases 20 percent while 7 percent decrease occurred at the rear of the train. The further simulation of moving stability of high-speed train is adopted, and the results show that the change of aerodynamic load which is caused by the roll angle has rare influence on derailment coefficient and overturning coefficient. As a result, the influence on aerodynamic performance of changing roll angle could be ignored when study the moving stability of high-speed train.