支板超声速冷流流场及液体喷流混合特性

支板流场和支板燃料喷流的混合效果对超燃冲压发动机的性能有重要影响。为了找出支板流场的特性以及支板构型对支板流场和支板液体喷流混合特性的影响,采用试验和数值两种手段对支板超声速冷流流场进行了初步研究,并对冷流情况下支板液体喷流的混合特性进行了试验研究。结果表明:支板后掠角对支板流场影响较大;支板尾部交错几何结构能形成具有强烈卷吸作用的涡流,加快支板后缘剪切层发展并促进燃料在主流当中的扩散,增强混合;侧喷支板横向喷流与后喷支板顺流喷射相比,燃料在主流当中扩散得更快,混合得更好。研究成果初步确定了不同构型支板的超声速冷流流场特征,得到了支板构型对支板液体喷流混合效果的影响,为进一步开展热态研究和指导支板的设计打下基础。

Investigation on supersonic cold flow and liquid jet over struts

The flow pattern in a scramjet combustor with a strut injector and the mixing effect of the fuel are critical as pects of the scramjet performance.Characteristics of non-reacting supersonic flows over struts were investigated experimentally and numerically,and the mixing performance of struts with liquid jets in non-reacting flow was studied experimentally.Results show that the flow field can be affected by sweepback angle greatly.The alternating-wedge struts produce intense vortices,which accelerate the diffusion of fuel in mainstream and enhance the mixing.Jets into erossflow make the diffuseness of fuel inmainstream more quickly and achieve better mixing,compared with parallel jets.