中文摘要：

以气体爆炸理论为基础，利用高精度的加权本质无振荡（WENO）格式对变截面管道中的瓦斯爆炸进行了数值模拟，探讨了变截面管道对瓦斯爆炸火焰传播的影响规律，得到了变截面管道造成瓦斯爆炸强度增大的结论．在此基础上，分析了障碍物、壁面和三波结构对瓦斯二次爆炸的影响．结果表明，经壁面反射后的激波和三波点的碰撞都能够诱导二次爆炸的产生．这些结论为瓦斯爆炸的预防、安全评估和防火防爆提供了重要的理论依据．

英文摘要：

With the basis of gas explosion theory, high accuracy WENO scheme is adopted for numerical simulation of methane explosion in variable cross-section tube. Influence of variable cross-section tube on flame propagation of methane explosion is addressed. It is found that, variable cross-section tube results in decrease of the intensity of methane explosion. On this basis, the influence of obstacle, wall and three shock wave structure on re-initiation is analyzed. The results suggested that the shock reflection on the wall and collision of triple points can induce re-initiation. These conclusions provide valuable theoretical basis for prediction of methane explosion, safety assessment and prevention of fire and explosion.