Abstract This paper explains the basic knowledge to understand the relationship between overpressure wave behavior and the structure of flame propagation, especially the effects of the ignition position and opening ratio on the combustion dynamics. The explanations are based essentially on the experimental investigations of premixed syngas/air explosions carried out at a constant equivalence ratio of 1 and the hydrogen volume fraction of 0.3 in a rectangular half-open combustion chamber. The initial temperature T0 and pressure p0 were 298 K and 0.1 MPa, respectively. The four ignition positions were set at 0, 150, 450 and 750 mm off the left of the combustion chamber. Four different opening ratios of the duct were employed, including 0.25, 0.5, 0.75, and 1. The obtained results show that ignited at IP0, the increased opening ratio would cause the distorted tulip flame to disappear, accompanied by the propagation direction change of flame front. At the same ignition position, when the opening ratio increased, the oscillation amplitude of overpressure, and the velocities of the right-hand and left-hand flame all rose, but the overpressure growth rate and maximum overpressure decreased. As the ignition position approached the opening end, the overpressure and the flame front oscillations became more intense. It is indicated that different ignition positions and opening ratios exerted obvious effect on the flame front propagation and the overpressure.

中文翻译：

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不同点火位置和开度比的预混合成气/空气混合气爆炸特性实验研究

摘要 本文阐述了理解超压波行为与火焰传播结构之间关系的基础知识，特别是点火位置和开度比对燃烧动力学的影响。这些解释主要基于在矩形半开燃烧室中以恒定当量比为 1 和氢气体积分数为 0.3 进行的预混合成气/空气爆炸的实验研究。初始温度 T0 和压力 p0 分别为 298 K 和 0.1 MPa。四个点火位置分别设置在离燃烧室左侧 0、150、450 和 750 毫米处。采用四种不同的风道开度比，包括 0.25、0.5、0.75 和 1。所得结果表明，在 IP0 下点燃，增大开度会使扭曲的郁金香火焰消失，伴随着火焰锋面传播方向的改变。在同一点火位置，当开度增大时，超压振荡幅度和左右手火焰速度均升高，但超压增长率和最大超压减小。随着点火位置接近开启端，超压和火焰锋面振荡变得更加强烈。结果表明，不同的点火位置和开度对火焰前沿传播和超压有明显的影响。超压振荡幅度、左右手火焰速度均上升，但超压增长率和最大超压下降。随着点火位置接近开启端，超压和火焰锋面振荡变得更加强烈。结果表明，不同的点火位置和开度对火焰前沿传播和超压有明显的影响。超压振荡幅度、左右手火焰速度均上升，但超压增长率和最大超压下降。随着点火位置接近开启端，超压和火焰锋面振荡变得更加强烈。结果表明，不同的点火位置和开度对火焰前沿传播和超压有明显的影响。