移动列车的风场特性及车桥联合随机风场同步数值模拟研究

Under the transverse wind, the coupling effect between wind, train, and bridge (track) significantly affect the operation safety and serviceability of the high-speed train. This project is proposed to develop a new fluctuating wind field input model for the coupling analysis of wind-train-bridge systems using both theoretical and experimental techniques, which include the model for fluctuating wind spectra of a moving train, correlation model between the moving arrays within a train, and the correlation model between the moving train and stationary spatial points of the bridge. This research will develop a novel joint simulation methodology for the fluctuating wind field including the stationary bridge system by significantly enhancing the computational efficiency of the current state-of-art methods. To be specific, based on Taylor’s frozen turbulence hypothesis, fluctuating wind spectra for moving vehicles, correlation model between the moving points as well as the correlation between the moving and stationary points will be developed from a theoretical perspective. The wind tunnel test will then be designed and conducted to measure the wind velocities for both the moving and stationary points within the wind field. The above proposed theoretical model will be verified and validated through spectral analysis of the experimental measurements. The results from this research can provide an accurate and efficient fluctuating wind input model for the coupling analysis of wind-train-bridge systems and, in particular, will provide an essential technical basis for development of the real-time operation warning system for high-speed train under strong wind.

当有横向风荷载作用时，风-列车-桥梁（线路）成为一个统一的整体，其耦合振动严重影响高速列车的运行安全及行车舒适性。本课题的主要目的是基于理论和实验手段建立一种新的风车桥耦合系统的随机风场模拟方法，主要包括移动列车的脉动风速谱、移动点间脉动风相关性及移动点与静止点的相关性的理论和试验研究；并在此基础上，建立一种新的车桥联合随机风速场同步数值模拟方法，大大改进现有模拟方法的效率。具体而言，基于“泰勒冻结”紊流假定，开展移动点的脉动风速谱、移动点间脉动风的相关性及移动点与静止点的相关特性研究；基于移动风速时程的风洞试验同步测试，同步采集多个移动点及少数几个静止点的脉动风速时程，通过谱估计及相关分析，对有关理论推导结果进行验证。本项目的研究成果可为风-列车-线路（桥梁）耦合分析提供高效且真实的随机风荷载输入，从而为开展高速列车的大风预警研究提供支撑。

当有横向风荷载作用时，风-列车-桥梁（线路）成为一个统一的整体，其耦合振动严重影响高速列车的运行安全及行车舒适性。本课题基于理论推导和实验手段，旨在建立一种新的风车桥耦合系统的随机风场模拟方法，并探讨移动列车的气功特性。主要研究内容包括：基于移动列车风速谱和相干函数理论推导及风洞试验模拟，建立车-桥系统联合风场模拟方法；基于风洞试验及CFD数值模拟，开展钢桁梁及简支梁上移动列车气动绕流特性模拟研究；同时，探讨局部风场作用下（桥塔遮蔽效应、风屏障遮蔽效应、双车交会）桥上移动列车的气动特性突变机理。研究结果显示，移动列车风速谱能量随着车速的增加会向高频移动，而移动相干函数的建立受静止风场相干函数及车速共同影响；采用FFT算法和频率截断技术建立的车-桥系统联合风场模拟方法可以实现车-桥系统随机风场的高效模拟；静止阶段模型无法真实还原桥上移动列车的气动特性，使得动、静态列车模型在测试气动力方面存在差异性，而移动列车气动特性同时受风速、风向、车速及桥梁整体绕流影响；桥塔遮蔽效应及双车交会会在结构本身一定放大区域内引起背风侧列车气动力的明显突变，列车动力响应也将发生明显变化；风屏障的合理布置可以有效减小上述突变效应，使得列车可以平稳地驶过局部突变风环境区域。本项目的研究成果可为风-列车-线路（桥梁）耦合分析提供高效且真实的随机风荷载输入，从而为开展高速列车的大风预警研究提供支撑。