地铁火灾的盐水实验与计算机数值模拟

为了认识地铁火灾烟气的流动规律，达到为消防设计提供相关资料并采取合理消防措施的目的，采用缩尺盐水实验与计算机计算流体力学数值模拟相结合的方法对地铁火灾进行研究．研究受限空间火灾烟气运动的手段主要有全尺寸火灾实验、小尺寸模拟实验和计算机数值模拟3种．实验模拟了列车着火和站台着火2种情况，得到了地铁火灾的烟气流动规律，比较并分析了计算流体力学数值模拟与盐水实验得出的烟层无量纲高度和无量纲时间．计算流体力学数值模拟与盐水实验得到的烟气到达楼梯口所需时间相差为1．5—2s，到达远侧楼梯口所需时间相差7．2s．二者之间存在着一定的误差，但误差不大．同一时刻，数值模拟比盐水实验得到的无量纲烟层高度高0．1左右，变化趋势一致．结果表明，实验条件选取合理，方程模型选用和边界条件设置恰当，盐水实验与计算流体力学数值方法模拟地铁火灾均是可行的．

Salt-Water Experiment and Computer Numerical Simulation of Subway Fire

A combination of small-scale salt-water experiments and computer computational fluid dynamics simulation was used to study the flowing rule of smoke in subway, so that suggestions can be given on fire control. There are three main methods in researching smoke flow in a confined space, namely the full-scale fire experiments, small-scale simulating experiments and computer numerical simulations. The states of fire on platform and in trains were simulated and the dimensionless height and dimensionless time of the smoke were are compared. The time difference of time when the smoke reached the nearer stairway in salt-water experiments and computational fluid dynamics simulation is 1.5 s-2 s, while the difference of time when the smoke reached the farther stairway in these two methods is 7.2 s. The dimensionless height of smoke layer obtained from numerical simulation is 0.1 higher than that obtained from experiments, but they have the same changing tendency. Experiments and computer simulation results show that it is feasible to simulate the subway fire by using salt-water experiments and computational fluid dynamics simulation if the experimental conditions and the function models are selected reasonably and the boundary conditions are set correctly.