发射燃气扩散过程数值模拟及安全性分析

Numerical Simulation and Safety Analysis of Fire Gas Diffusion Process

目的研究发射燃气扩散过程及对附近安全的影响。方法以CFD方法建立发射阵地气体扩散数学模型,空间内的湍流采用RNG k-ε湍流模型,结合FLUENT软件,对某燃气发生器产生的有毒气体的扩散过程进行数值模拟。以氯气为标的物,计算不同风速、地形影响下氯气的扩散过程,分析风速、山地对氯气扩散速度、距离、覆盖范围、浓度变化的影响。结果山顶发射时,风速越大,氯气的扩散速度越快,覆盖范围越广,最大扩散距离为249 m;山底发射时,在相同风速下,氯气的扩散距离、扩散速度均小于山顶发射时,最大扩散距离为221 m。山地对氯气扩散的影响主要是减缓氯气团的运动速度,减小氯气的影响距离,在山地的迎风面与背风面氯气浓度较高。结论不同风速和起伏山地对氯气扩散会产生较大影响,采用该分析方法可以归纳出有毒气体扩散及影响范围的一般规律。

Objective To study the process of fire gas diffusion and its impact on nearby safety.Methods A mathematical model of gas diffusion was established at the launching position by CFD method.And the RNG k-εturbulence model was adopted for turbulence in the space to numerically simulate the diffusion process of toxic gases produced by a gas generator with FLUENT software.The diffusion process of gas at different wind speed and under different terrain influences was calculated with chlorine as the target.The effects of wind speed and mountain on the diffusion speed,distance,coverage and concentration of chlorine were analyzed.Results When fired on the top,the higher the wind speed was,the faster the diffusion rate of chlorine and the wider the coverage were.The maximum diffusion distance was 249 m.When fired at foot,at the same wind speed,the diffusion distance and diffusion speed of chlorine gas were smaller than those on the top.The maximum diffusion distance was 221 m.The influence of the mountain on the diffusion of chlorine gas was mainly to slow down the movement speed of chlorine gas group and reduce the influence distance of chlorine gas.The concentration of chlorine in the windward and leeward sides of the mountain was higher than other places.Conclusion Different wind speeds and undulating mountains have great influences on the diffusion of chlorine gas.The general rule of diffusion and influence range of toxic gases could be summarized by this analysis method.