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转弯结构是煤矿巷道最基本的建筑单元之一.研究转弯结构对井下瓦斯爆炸的影响规律有助于煤巷抗爆能力评估和优化设计.基于此,借助数值模拟研究了不同转弯条件下转弯前直巷道内局部瓦斯爆炸流场,重点分析了转弯前直巷道内冲击波传播规律.研究表明:对于同一转弯结构,越靠近转弯位置,与直巷道内相应位置处的爆炸冲量的差异越明显;对于不同的转弯结构,转弯角度越大,与直巷道相应位置处的爆炸冲量的差异则越大.基于反射波对转弯前直巷道内原始冲击波的影响,建立了临界尺度距离随转弯角度的定量关系.在转弯处,爆炸冲量随转弯角度的增加而增大,与直巷道相应位置处的爆炸冲量相比,其增长比例随转弯角度的增大呈非线性增长.“,”The bend structure is one of the most basic building elements of a coal tunnel.A good understanding of its influence on the gas explosion is essential for estimating the tunnel's blast resistance and thus for optimizing the tunnel's design.In the present work,we studied the influence of the bend structure on shockwaves in the straight tunnel before and at the bend under premixed methane-air explosion using numerical simulations.The shockwave propagation in the straight tunnel before the bend was analyzed.For a one-bend tunnel,the closer to the bend,the more obvious the difference between the impulse at this location and that at the same location in a straight tunnel.For tunnels with different bend angles,the larger the bend angle,the greater the change in the impulse compared with that at the corresponding location in a straight tunnel.Based on the influence of the reflected shockwave on the original shockwave in the straight tunnel before the bend,the relation of the critical scaled distance with the bend angle was established.At the bend,as the bend angle increases,the impulse here increases,and its increase percentage compared with that at the corresponding location in a straight tunnel changes as well,whose relation was also proposed.