Abstract In order to reveal the propagation characteristics and hazards of a gas explosion in urban drainage pipeline, the dynamic evolution of a methane deflagration in a closed water-containing pipeline was numerically simulated based on Computational Fluid Dynamics (CFD). The interaction mechanism between water oscillation and flame development during the methane deflagration was such revealed. The results show that the presence of water accelerates the flame propagation in the forward accelerating stage. However, the water generally played a significant role in inhibiting the flame propagation because of its cooling and blocking effects. And the flame acceleration may be enhanced with the water present if a longer tube is employed. The shear force generated by the compression wave acting on the stagnant water surface provides the most primitive power for the movement of water, which creates ripples in the calm water. The obstacles and the reciprocating motion of the compression wave make the water ripple and evolve into lifting thin water columns. The shearing effect of high-speed gas flow evolves the water columns into discrete water droplets. This evolution process of the water body increases the contact area between water and flame, thus blocking the transfer of heat and the expansion wave, inhibiting the self-sustained flame propagation, leading to its gradual extinction.

中文翻译：

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封闭管道天然气爆燃火焰与连续水耦合机理

摘要 为揭示城市排水管道瓦斯爆炸的传播特征及危害，基于计算流体动力学（CFD）对封闭含水管道中甲烷爆燃的动态演化进行了数值模拟。揭示了甲烷爆燃过程中水振荡与火焰发展的相互作用机制。结果表明，水的存在加速了向前加速阶段的火焰传播。然而，由于水的冷却和阻挡作用，水通常在抑制火焰传播方面发挥了重要作用。如果使用更长的管子，则可以通过存在水来增强火焰加速。压缩波作用于停滞的水面所产生的剪切力为水的运动提供了最原始的动力，从而在平静的水中产生涟漪。障碍物和压缩波的往复运动使水波纹演变成提升的细水柱。高速气流的剪切效应使水柱演变成离散的水滴。水体的这种演化过程增加了水与火焰的接触面积，从而阻碍了热量的传递和膨胀波，抑制了火焰的自持传播，导致其逐渐熄灭。障碍物和压缩波的往复运动使水波纹演变成提升的细水柱。高速气流的剪切效应使水柱演变成离散的水滴。水体的这种演化过程增加了水与火焰的接触面积，从而阻碍了热量的传递和膨胀波，抑制了火焰的自持传播，导致其逐渐熄灭。障碍物和压缩波的往复运动使水波纹演变成提升的细水柱。高速气流的剪切效应使水柱演变成离散的水滴。水体的这种演化过程增加了水与火焰的接触面积，从而阻碍了热量的传递和膨胀波，抑制了火焰的自持传播，导致其逐渐熄灭。