随机风作用下高速列车非定常气动载荷的计算方法

Algorithm for the unsteady aerodynamic loads of high-speed trains under stochastic winds

基于Cooper理论和谐波叠加法计算随车移动点的脉动风速,分析不同风向角下脉动风速的功率谱密度特性。在横风下高速列车非定常气动载荷计算方法的基础上,建立了侧风下高速列车非定常气动载荷的计算方法,并用此方法分析了侧向随机风作用下非定常气动载荷的统计特性,给出了各气动载荷的峰值因子。研究表明,当风向角接近90°时,无量纲功率谱会往高频移动,风向角对脉动风速的影响较小;在各个风向角下,气动载荷的标准差与平均值的比值仅依赖于侧偏角,侧力与侧滚力矩的峰值因子相同,摇头力矩与点头力矩的峰值因子相同。

The fluctuating winds of a moving point shifting with trains are calculated in this paper based on Cooper theory and harmonic superposition method. And the characteristic of power spectral density of fluctuating winds is analyzed. An algorithm is proposed to calculate the unsteady aerodynamic loads of high-speed trains under side-winds based on the algorithm of calculating cross wind forces of high-speed trains. The force statistics under side stochastic winds and the peak factors of aerodynamic loads are ana- lyzed using this algorithm. The results show that,when the wind angle is close to 90,the dimensionless power spectrum is moving to a higher frequency range. The wind angle has little effect on the fluctuating wind. At each wind angle, the ratio of load standard deviation to mean load depends only on the side slip angle. The peak factors of the side force and roll moment are the same, and the peak factors of the yaw moment and pitch moment are also the same.