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为了研究管道预混火焰的传播特性及内在机理,运用数值模拟的方法,建立矿井瓦斯气体爆炸的数学模型和物理模型,对不同当量比浓度的矿井瓦斯气体爆炸过程进行模拟研究。计算结果表明,矿井瓦斯气体爆炸过程中速度和压力值均会经历上升-下降-二次波峰-下降-震荡的过程。火焰传播初期,气体爆燃体积迅速增大,火焰的速度、压力和温度随之迅速上升,并在一段时间内呈现层流燃烧状态。而后速度和压力图均出现了不同程度的波动,可知这是压力波和反射波共同作用的结果。速度和压力并未同时达到峰值,速度要超前于压力达到最大状态,这主要是爆炸压力波和反射压力波的相互叠加作用导致压力上升,而反射压力波导致速度下降。当量比浓度的压力、速度值最小,燃烧持续时间最长,此时气体还未完全加速,未形成爆轰状态。
In order to study the propagation characteristics and inherent mechanism of premixed flames in pipeline, a mathematical model and a physical model of mine gas explosion are established by numerical simulation. The gas explosion process of mine with different equivalent and specific concentration is simulated. The calculation results show that both the velocity and the pressure in the process of gas explosion in mine will go through the process of ascending-descending-second peak-descent-concussion. In the early stage of flame propagation, the volume of gas deflagration increased rapidly, and the speed, pressure and temperature of the flames rose rapidly, and the laminar-flow combustion state appeared in a period of time. And then the velocity and pressure maps have shown varying degrees of fluctuations, we can see that this is the result of pressure and reflection waves together. Speed and pressure did not reach the peak at the same time, and the speed should be higher than the maximum pressure. This is mainly caused by the mutual superposition of the explosion pressure wave and the reflection pressure wave, which causes the pressure increase, and the reflection pressure wave causes the speed decrease. Equivalent than the concentration of pressure, speed, minimum value, the longest combustion duration, the gas has not yet fully accelerated, did not form a detonation state.