中文摘要：

为研究随机风作用下高速列车的非定常气动载荷,基于COOPER理论和谐波叠加法计算随高速列车移动的点的脉动风,分析车速和平均风速对量纲一功率谱密度的影响。采用计算流体动力学方法数值计算气动载荷系数随侧偏角的变化规律,研究随机风作用下高速列车非定常气动载荷的计算方法,并推导出非定常气动载荷的概率分布特性。通过仿真分析车速为200～400 km/h,平均风速为10～35 m/s时的脉动风和非定常气动载荷发现,量纲一功率谱密度随车速的增加往高频部分移动,平均风速的变化对其影响较小;平均风速对脉动风速的影响大于车速对脉动风速的影响;当考虑侧偏角的变化时,计算得到的非定常气动载荷的波动增大;采用准定常法和改进准定常法计算得到的非定常气动载荷具有随机过程的遍历性,而采用权重函数法及改进权重函数法计算得到的非定常气动载荷不具有随机过程的遍历性。

英文摘要：

To study the unsteady aerodynamic forces of high-speed trains under stochastic winds, the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based On COOPER theory and harmonic superposition method. The effects of train speeds and average wind speeds on the dimensionless power spectra! density are analyzed. The computational fluid dynamics method is used to obtain the aerodynamic load coefficients at different slip angles. The unsteady aerodynamic load calculation methods for high-speed trains under fluctuating winds are studied and the probability distribution of unsteady aerodynamic loads is derived. The fluctuating winds and the unsteady aerodynamic loads of high-speed trains under train speeds of 200-400 kin/h, and average wind speeds of 10-35 m/s are calculated and the results show that the dimensionless power spectral density is moving to a higher frequency range with the increase of train speeds, while the average wind speeds have little effect on it. The average wind speeds have a more significant impact on fluctuating winds than the average train speeds do. When considering fluctuation of the slip angles, fluctuation of the unsteady aerodynamic loads increases. The unsteady aerodynamic loads obtained using the quasi-steady method and the modified quasi-steady method have the characteristic of ergodicity of random processes. While the ones obtained using the weighting function method and the modified weighting function method do not have this characteristic.