等离子体射流作用下光壁面超声速燃烧室点火试验研究

针对光壁面超声速燃烧室的点火需求，利用中心嵌入式等离子体射流在模拟马赫数6，总温1860K的直连式试验台上实现了煤油燃料的可靠点火和稳定燃烧，研究了超声速燃烧室起动过程中等离子体建立与维持特征，获取了不同当量比下火焰传播与燃烧特性。试验表明：在自身工质的高压射流维持下，等离子体点火器可以在点火起动的不同压力变化环境中保持稳定；中心等离子体射流产生一定尺度的高温区域且含有丰富的自由基，但需要在恰当的中心喷油流量形成的混气当量比下产生等离子体诱导火焰；诱导火焰沿燃烧室轴向传播进而发展形成了稳定的超声速燃烧。

Experimental Study on Plasma Jet Enhanced Ignition in No-Cavity Supersonic Combustor

Aiming at the requirements of the no-cavity supersonic combustion, a central embedded plasma jet was used to achieve reliable ignition and stable combustion of kerosene fuel in direct-connected test facility with simulated Mach 6 and total temperature of 1860K. The characteristics of plasma during the establishment and maintenance process were studied. Flame propagation and combustion characteristics were obtained at different equivalence ratios. Tests results showed that the plasma jet can be stable under the maintenance of high-pressure jets of its own working medium, and that the central plasma jet can generate a certain size of high temperature area and contains abundant free radicals. Plasma-induced flames could only be generated at a certain local fuel equivalent ratio. The produced flames propagated along the axial direction of the combustion chamber to develop a stable supersonic combustion.