【摘要】 高速列车从明线进入狭窄隧道时，在隧道出口将产生“音爆”，即微气压波。当磁悬浮列车速度达到600 km/h时，车隧耦合气动效应急剧增强。因此，亟待探索新的气动效应缓解方法。本文提出了一种新型趋线性方法，即通过改变隧道缓冲结构开孔率，分析初始压缩波和微气压波特性，得到初始压缩波压力常梯度，进而缓解隧道出口处的微气压波。研究结果表明，随着隧道缓冲结构开孔率的增加，隧道出口微气压波幅值先减小后增大。当开孔率为2.28%时，初始压缩波曲线斜率与新型趋线性方法中假定直线重合。与未开孔缓冲结构相比，微气压波幅值在隧道出口20 m和50 m处分别进一步减少26.9%和20.0%。因此，本文提出的方法有效缓解了隧道出口微气压波，并能快速得到在特定车/隧运行条件下微气压波幅值的缓解上限。研究成果将为隧道缓冲结构自适应设计提供一种全新的方法。更多还原

【Abstract】 A high-speed train travelling from the open air into a narrow tunnel will cause the “sonic boom” at tunnel exit. When the maglev train’ s speed reaches 600 km/h, the train-tunnel aerodynamic effect is intensified, so a new mitigation method is urgently expected to be explored. This study proposed a novel asymptotic linear method(ALM) for micro-pressure wave(MPW) mitigation to achieve a constant gradient of initial compression waves(ICWs), via a study with various open ratios on hoods. The properties of ICWs and MPWs under various open ratios of hoods were analyzed. The results show that as the open ratio increases, the MPW amplitude at the tunnel exit initially decreases before rising. At the open ratio of 2.28%, the slope of the ICW curve is linearly coincident with a supposed straight line in the ALM, which further reduces the MPW amplitude by 26.9% at 20 m and 20.0% at 50 m from the exit, as compared to the unvented hood. Therefore, the proposed method effectively mitigates MPW and quickly determines the upper limit of alleviation for the MPW amplitude at a fixed train-tunnel operation condition. All achievements provide a new potential measure for the adaptive design of tunnel hoods.更多还原