当量比对超声速燃烧室性能影响的数值研究

摘要

采用欧拉⁃拉格朗日法在来流 Ma＝2的条件下，对带支板凹腔组合结构的煤油超燃燃烧室的内流场进行数值计算，分析了燃烧室下游支板不同当量比对燃烧室燃烧流场的影响，并对燃烧室的性能做了定量分析。研究表明，随下游支板燃料当量比增加，燃烧反压对燃烧室上游影响加重，流动分离区扩大，上游燃料发生亚声速燃烧状态，且亚声速燃烧区域变大。在支板和凹腔共同作用下，凹腔后方形成了亚声速燃烧区和超声速燃烧区，当量比增加时超声速燃烧区减小，亚声速燃烧区扩大，从而有利于燃料的充分混合和燃烧。随当量比增加，燃烧室总压恢复系数和推力增加，燃料消耗率和比冲量减小。%The flow field in the supersonic combustor with strut/ cavity configuration was numerically calculated by using the Euler Lagrange method at Mach 2.The characteristics of the flow field in combustion were analyzed by changing the equivalence ratio and the quantitative performance of the combustor was got.The results show that the effect of combustion back pressure on flow up⁃stream becomes higher with the equivalence ratio increasing,resulting in an expansion of the flow separation and a larger subsonic combustion region.The strut/ cavity configuration makes the flow into two parts downstream the cavity: supersonic flow and subsonic flow.The supersonic combustion region becomes smaller,but the subsonic combustion region becomes larger with the equivalence ra⁃tio increasing,enhancing the mixture efficiency and full combustion.The total pressure coefficient and the momentum increase largely but the combustion efficiency and specific impulse becomes smaller with the equivalence ratio increasing.