Ma4下超燃发动机乙烯点火及火焰传播过程试验研究  

Experimental research on ethylene ignition and flame propagation processes for scramjet at Ma4

作　　者：张弯洲[1,2] 乐嘉陵[2] 杨顺华[2] 程文明[1] 邓维鑫[1,2] 

机构地区：[1]西南交通大学机械工程学院,成都610031 [2]中国空气动力研究与发展中心吸气式高超声速技术研究中心,四川绵阳621000

出　　处：《实验流体力学》2016年第3期40-46,84,共8页Journal of Experiments in Fluid Mechanics

摘　　要：在直连式脉冲燃烧设备上,开展了模拟Ma4,总温935K来流参数下的超燃发动机乙烯点火试验。试验利用了火炬点火器和引导氢气的辅助点火方式,实现了乙烯的点火和稳定燃烧。结合壁面压力测量、高速摄影和数值模拟方法,分析点火及火焰传播过程发现:(1)在现有的注油方式下,回流区有利于点火,剪切层和凹槽后部是稳焰的主要区域;(2)点火成功后,影响凹槽稳焰的主要因素为燃料与氧化剂的浓度,剪切层内和凹槽后部持续卷吸氧化剂,因而能够维持稳定的燃烧;(3)凹槽下游注入的燃料发生燃烧造成流道一定程度壅塞,是提升燃烧室压力水平的重要原因,但该处的燃烧不能够稳定,引起燃烧室内压力的振荡,而导致该处不稳定燃烧的2个主要因素为变化的氧含量和较高的流速。Gaseous ethylene ignition experiments were carried out on directly-connected pulse combustion facility.The stagnation temperature and the Mach number at the isolator entrance were 935 Kand 2respectively,which simulated the flight with Mach number 4.Ethylene was ignited successfully and stable combustion was maintained by employing torch igniter and pilot hydrogen.Wall pressure measurement,high speed imaging and numerical simulation were employed to analyze the ignition and flame propagation processes.The results indicate that：（1）the recirculation zone in the cavity avails ignition,while the shear layer and the rear of the cavity are the main regions for stable combustion;（2）after ignition,the density of the fuel and oxidizer is the key factor to stable combustion,and oxidizer that continually entering the shear layer and rear of cavity supports the stable combustion;（3）combustion downstream of the cavity promotes the pressure level in the combustor,and the unstable combustion there causes pressure oscillation.The high velocity and variation of oxygen content are the two main factors including unstable combustion downstream of the cavity.

关 键 词：超燃发动机 点火 火焰传播 脉冲燃烧风洞 稳定燃烧 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]