With the development of the society, train travels in underground, mountain, and undersea tunnels are common public-transportation scenarios. Relative research such as ventilation, environment, and disaster of the tunnel is concerned and important for the sustainable cities. Piston wind which is induced by trains plays an important role of tunnel research. In this study, theoretical models are established for the piston wind and validated by the experiments. The effects of five key factors on the piston wind are studied. Grey correlation analysis is adopted and the results reveal that the blockage ratio has the most significant influence on the piston wind. A universal fitting formula combined five influencing factors is obtained. Moreover, comparisons of the piston winds induced by two trains and a single train are conducted. The maximal piston wind velocity induced by two trains is equal to that of a single train with twice its length and lower than twice the maximal velocity induced by a single train. Finally, a general model for the precise prediction of variations in the piston wind induced by multiple trains is developed. This study contributes to the design of multi-train tunnels and the energy-saving operation of tunnel ventilation systems.

随着社会的发展，地下，山区和海底隧道中的火车旅行是常见的公共交通场景。诸如通风，环境和隧道灾难等相关研究受到关注，对可持续城市具有重要意义。火车引起的活塞风起着隧道研究的重要作用。在这项研究中，建立了活塞风的理论模型，并通过实验进行了验证。研究了五个关键因素对活塞风的影响。采用灰色关联分析，结果表明阻塞比对活塞风影响最大。得到了结合五个影响因素的通用拟合公式。此外，比较了由两列火车和一列火车引起的活塞风。两列火车所感应的最大活塞风速等于一列火车的最大风速，其长度是其两倍，并且低于一列火车所感应的最大风速的两倍。最后，建立了用于精确预测由多列火车引起的活塞风变化的通用模型。该研究有助于多线隧道的设计和隧道通风系统的节能运行。