激光点火技术因其位置灵活、能量密度高、释热速率快等优点，在航空航天动力系统中得到了广泛关注，其主要靠等离子体的气动、热和化学三大效应发挥作用。本文以甲烷/空气混合物的定容燃烧室内进行激光点火实验为基础，重点研究单脉冲激光诱导点火的火焰传播特性，分析了激光脉冲能量对点火和火焰传播特性的影响，通过数值模拟研究来评估等离子体化学效应的在点火过程中的作用机制。研究发现，初始火焰核呈现三瓣形结构，这与激光诱导空气击穿所形成的涡环结构极为相似，验证了等离子体气动效应在点火及热核发展中的重要作用。进一步对比分析了有/无化学效应下点火火焰核发展特性，结果表明相比等离子体的气动效应以及热效应，化学效应对火焰核的发展影响甚微。

Laser ignition technology has received widespread attention in aerospace power systems due to its flexible positioning, high energy density, and fast heat release rate. It mainly relies on the aerodynamic, thermal, and chemical effects of plasma. This article is based on laser ignition experiments conducted in a constant volume combustion chamber of methane/air mixture. The focus is on studying the flame propagation characteristics of single pulse laser-induced ignition, analyzing the influence of laser pulse energy on ignition and flame propagation characteristics, and conducting numerical simulation studies to evaluate the influence of plasma chemical effects. Research has found that the initial flame nucleus exhibits a three lobed structure, which is very similar to the vortex ring structure formed by laser-induced air breakdown, verifying the important role of plasma aerodynamic effects in ignition and thermonuclear development. Further comparative analysis was conducted on the development characteristics of ignition flame nuclei with and without chemical effects. The results showed that compared to the aerodynamic and thermal effects of plasma, chemical effects had little effect on the development of flame nuclei.