超声速燃烧室氢气强迫点火过程实验

Experimental Study on the Forced Ignition of Hydrogen in a Supersonic Combustor

模拟飞行Ma=4.0的超燃冲压发动机的燃烧室进口条件,在直连式试验台上对超燃冲压发动机氢气火花塞点火过程进行了研究。通过高速摄影与高速纹影捕捉了点火过程初始火焰发展与流程波系演化过程。结果表明,初始火焰传播受高速对流、湍流火焰传播和自点火多种机制控制,凹腔结构不仅提供低速环境,还在初始火焰传播过程中具有能量反馈和质量反馈(活化分子)作用,促进剪切层内火焰的发展。

The spark ignition process of hydrogen was investigated in a direct-connect supersonic combustor. The entrance parameter of combustor corresponds to Scramjet flight Mach number 4. 0. The spark ignition process was observed by the high speed camera and Schlieren system. Experimental results have shown that the process of the early flame is controlled by sever- al different mechanism of high speed convection, turbulent flame propagation and self-ignition. The cavity does not only offer a low speed environment, but also forms a feedback mechanism of the heat and active radical species which promote the up- stream propagation in the shear layer.