变阻障碍物对管道内瓦斯爆炸的影响

Influence of Variable Resistance Obstacle on Gas Explosion in Pipeline

为探究障碍物阻塞比变化率对瓦斯爆炸的影响,分别建立平均阻塞比为0.6、0.3的受限空间物理模型,基于Charlette湍流燃烧模型,利用Fluent软件对阻塞比变化率依次为0、0.05、0.10、0.15的障碍物条件下的爆炸火焰、湍流转捩、压力波耦合过程进行大涡模拟(LES)。研究结果表明:火焰经过障碍物会产生回流卷吸效应。在平均阻塞比为0.6的工况组A中,当阻塞比变化率为0.10、0.15时,火焰锋面更加尖锐,火焰传播速度峰值更高,平均传播速度更高,到达超压所需时间更短,超压峰值更大。在平均阻塞比为0.3的工况组B中,各工况平均传播速度相同,随着阻塞比变化率的增大,到达超压所需时间更长,超压峰值更大。

In order to explore the influence of obstacle blocking ratio gradient in underground coal mine on gas explosion,physical models of confined space with an average blocking ratio of 0.6 and 0.3 were established respectively.Based on the Charlette turbulent combustion model,large eddy simulation(LES)of explosive flame,turbulent transition and pressure wave coupling process under the conditions of obstacles with blocking ratio change rates of 0,0.05,0.10 and 0.15 was carried out by using Fluent software.The results show that the backflow coiling effect occurs when flame passes through obstacles.In Group A with the average blocking ratio of 0.6,when the blocking ratio change rate is 0.10 and 0.15,the flame front is sharper,the flame propagation velocity peak is higher,the average propagation velocity is higher,the time to reach the overpressure is shorter,and the overpressure peak is larger.In Group B with the average blocking ratio of 0.3,the average propagation speed of each working condition is the same.With the increase of the change rate of blocking ratio,it takes longer time to reach the overpressure,and the overpressure peak is larger.