Abstract With the rapid development of subway systems, the related fundamental knowledge is critically needed to benefit their designs and fire hazard assessment. The experimental study was performed in a 1/5th scale subway train model to characterize the fire inside subway train, and the experiment in open space was also conducted as a control group. Results show that in the case where the ceiling flame has not yet propagated to the sidewalls of the subway train, the normalized ceiling flame length varies as 1/4 power of the non-dimensional ceiling heat release rate. In addition, the temperature distributions at different transverse distances from the fire source follow the exponential decay law effectively, the decay rate is indeed a function of normalized transverse distance from the longitudinal centerline. An empirical model involving dimensionless transverse and longitudinal coordinates is proposed to predict the two-dimensional temperature underneath the ceiling, which is reasonably well fitting with experimental results from this study and literatures.

中文翻译：

---

地铁列车内火灾特性及蔓延的实验研究

摘要 随着地铁系统的快速发展，急需相关的基础知识来帮助其设计和火灾危险评估。实验研究在 1/5 比例的地铁列车模型中进行，以表征地铁列车内部的火灾，并在开放空间中进行实验作为对照组。结果表明，在天花板火焰尚未传播到地铁列车侧壁的情况下，标准化的天花板火焰长度以无量纲天花板热释放率的1/4次方变化。此外，距火源不同横向距离处的温度分布有效地遵循指数衰减规律，衰减率确实是距纵向中心线的归一化横向距离的函数。