注油方式对超燃冲压发动机燃烧性能的影响

Effect of fueling scheme on scramjet combustion performance

基于脉冲燃烧风洞直连式试验平台,利用壁面压力测量和高速摄影等手段,研究了注油方式对超燃冲压发动机燃烧性能的影响.考察了不同油位单点注油时的注油特性,利用高速摄影揭示了各个油位的火焰发展历程.在产生有效推力及防止进气道不起动的限制下,确定了各个油位的贫油最低当量比、富油最高当量比.研究了第1油位、第2油位和其他油位组合注油时的耦合作用.以隔离段未扰动区域长度、燃烧室内推力、燃料比冲为指标,探寻了燃烧性能最佳的注油方式.试验获得的隔离段未扰动区域长度最大为149.6mm,燃烧室内推力最大为1 622.3N,燃料比冲最大为1 354.0s.

Effect of fueling scheme on scramjet combustion performance was investigated based on pulse wind-tunnel direct connected experiment platform.Both pressure measurement and high speed videos were employed.The time evolution of flame with ethylene injected at different single injectors was demonstrated by high speed videos.Under the limits of producing effective thrust and avoiding inlet un-start,the first and second injectors＇ least and largest fuel equivalence ratios（ER） for combustion were obtained from injecting characteristics experiments.The coupling of the first and second injectors with others was studied.With these initiatory results gained above,different fueling schemes for best combustion performance were investigated under three indexes：isolator undisturbed length,combustor inner thrust and fuel specific impulse.The optimum values for these three indexes were 149.6 mm,1 622.3 N and 1 354.0 s separately.