注油分布对超燃冲压发动机燃烧性能的影响

Numerical Investigation Combustion Performance of Fueling Scheme on Scramjet Combustor

通过对三维单凹槽两段扩张的超燃燃烧室进行三维大规模并行数值模拟,重点探讨了注油分布对超燃燃烧室燃烧性能的影响。燃烧室入口马赫数2.0、静温937 K、静压0.8 MPa、乙烯总当量比1.0,注油位置采用凹槽内单点注油和凹槽前单点注油。结果表明:在凹槽前单点注油情况下,随着当量比的提高燃料燃烧越来越剧烈,主流道内高Mach数区域逐渐减小,由超燃过渡到亚燃;随着当量比的提高,发动机壁面压力提升明显;如果当量比进一步提高,反压可能扰出隔离段,影响进气道的起动;当凹槽内单点注油和凹槽前单点注油当量比0.315时,燃烧性能差别不大,燃烧模态一致,壁面压力差别较小。

The effect of fuel injection distribution on the combustion performance of a three-dimensional single-grooved two-stage expanded combustor was investigated by large-scale parallel numerical simulation. Under the inflow air condition Mach number 2. 0,the static temperature 937 K,the static pressure0. 8 MPa,and the total equivalence ratio of ethylene 1. 0,the single point oil injection in the groove and the single point oil injection before the groove were adopted. The results show that when the fuel is injected at a single point in front of the Groove,with the increase of the equivalence ratio,the fuel combustion becomes more and more intense,and the Mach number region in the main channel decreases gradually,from supercombustion to subcombustion. With the increase of the equivalence ratio,the pressure on the engine wall increases obviously. If the equivalence ratio is further increased,the back pressure may disturb the isolator and affect the start-up of the inlet. When the equivalence ratio of single-point oil injection in the groove to the single-point oil injection before the groove is 0. 315,the combustion performance has little difference,the combustion mode is consistent,and the wall pressure has little difference.