中文摘要：

基于计算流体动力学理论,采用数值模拟的方法计算设置有不同高度风障的双线简支箱梁桥上高速列车的气动力,分析绕列车几何中心、迎风侧轮轨接触轴线和背风侧轮轨接触轴线的侧倾力矩,提出控制侧倾力矩和累计控制侧倾力矩的概念,并以此为依据通过不断逼近的方法得到最优的风障高度,最后对风障改善列车气动性能的机理进行研究。研究结果表明：风障的高度对列车的气动力影响较大,但根据各分力得出的最优风障高度不一致;侧倾力矩对轮轨接触轴线比几何中心大,且对风障高度也更加敏感;控制侧倾力矩当风障高度较小时为对背风侧轮轨接触轴线之矩,当风障增加到一定高度后,将转移到迎风侧轮轨接触轴线,从而对于双线桥最优风障高度并不是对背风侧或迎风侧轮轨接触轴线侧倾力矩为0 N·m的风障高度;综合考虑列车位于两线路上的气动作用,根据累计控制侧倾力矩得出气动缩尺模型的最优风障高度为95 mm,从而可知双线高速铁路简支箱梁桥上1.9 m风障效果最好。

英文摘要：

Based on the theory of computational fluid dynamics, the aerodynamic forces of high-speed train on simply supported box-girder bridge installed with wind barriers of various height were computed by numerical simulation. The rolling moment to the geometric center of train, windward axis of wheel-rail contact and leeward axis of wheel-rail contact were analyzed. The concepts of control rolling moment and summed control rolling moment were proposed, and the optimal height of wind barriers was found according to the concepts through approximation method. The mechanism of the improvement of wind barriers to aerodynamic performance of train was studied. The results show that the height of wind barriers has significant effect on the aerodynamic forces of train, and the optimal height is different according to different components. The rolling moment to wheel-rail contact axis is larger than that to geometric center, and is more sensitive to wind barriers height. The control rolling moment is to leeward axis of wheel-rail contact when the wind barriers is low, and it will transfer to windward axis of wheel-rail contact when the height of wind barriers increases to some value, and furthermore, the optimal height of wind barriers isn’t the height that caused the rolling moment to windward or leeward axis of wheel-rail contact to 0 N·m for double lines bridge. In consideration of aerodynamic forces of train on both lines, the optimal height of wind barriers of aerodynamic scale model is 95 mm according to summed control rolling moment. It is known that the optimal height of wind barriers is 1.9 m on high-speed railway of simply supported box-girder bridge with double lines.