相对风速对高铁车厢火灾烟流及温度分布的影响

为探究相对风速对高速列车车厢火灾烟流及温度分布的影响，利用PyroSim建立我国复兴号某型二等座车厢火灾数值计算模型。在着火后3 min关闭外端门条件下，研究车窗破裂状态及不同的相对风速对车厢火灾烟流及温度分布的影响，评估火灾作用下高架桥列车运行的安全性。结果表明：对于人为砸碎应急逃生窗的情况，无论是形成单侧开口还是对流开口，对客室内部整体温度没有明显影响，火灾初期车厢火势主要向逃生窗破裂一侧蔓延；随着相对风速的增加，车厢走道温度降低，烟气抵达两侧客室端门的时间延长；在火灾初期，相对风速的增加对两侧通过台的冷却和排烟作用较为明显，缩小了危险区的范围；50 s前火源点附近很小范围为轻危险区，大致在（-2，2） m，车厢走道大多处在安全区，是人员逃生的最佳时段，综合考虑人员疏散及火势的蔓延情况，提出列车车厢发生火灾后安全运行速度为40 km/h。

The influence of relative wind speed on the smoke flow and temperature distribution in high-speed railway carriage fire

In order to explore the influence of relative wind speed on the smoke flow and temperature distribution of high-speed train carriage fire, PyroSim was used to establish a numerical calculation model for fire of a certain type of second-class carriage of China Renaissance. Under the condition of closing the outer doors 3 min after the fire, the influence of the ruptured states of the windows and different relative wind speeds on the smoke flow and temperature distribution of carriage fire was studied, and the safety of the train operation on viaduct under the fire was evaluated. The results show that: for the case of artificially smashing the emergency escape windows, the unilateral opening or the convection opening has no obvious effect on the overall temperature inside the passenger carriage. In the early stage of the fire, the fire mainly spreads to the ruptured side of the escape windows. As the relative wind speed increases, the temperature of carriage aisle decreases, and the time of the smoke reaching the end door of the passenger carriage on both sides increases. In the early stage of the fire, the increase of relative wind speed has more obvious effects on the cooling and smoke exhaust through the platforms on both sides, reducing the scope of the dangerous zone. A small area near the fire source before 50 s is a light-hazard area, roughly (-2, 2) m. The carriage aisle is mostly in the safe area, and the period before 50 s is the best time period for people to escape. Considering the personnel evacuation and the spread of fire, it is proposed that the safe operating speed of the train after a fire is 40 km/h.