等离子体射流作用下光壁面超声速燃烧室点火试验研究

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

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6、总温1680K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,其在恰当的混气当量比下会产生等离子体诱导火焰;诱导火焰沿燃烧室轴向传播并发展形成了稳定的超声速燃烧。

For the ignition requirements of the no-cavity supersonic combustor,a central embedded plasma jet was proposed to enhance ignition and stabilize combustion,in the direct-connected test of kerosene supersonic combustion under the simulated condition of Ma 6 and the total temperature of 1680 K. The plasma characteristics during the ignition establishment and development process were studied,and the plasma-ignited flame characteristics at different equivalence ratios were obtained. The research results showed that the plasma jet always maintained stable with the high-pressure jet of its own working medium during the varied pressure ignition process. A spatial region with high temperature and a large amount of active radicals was produced at the downstream of plasma jet,which was useful to initiate a supersonic ignition at an appropriate mixing equivalence ratio.The plasma-ignited flames propagated along the axial direction of the chamber and developed a stable supersonic combustion.