Influence of Geometrical Configuration on the Fuel Mixing Performance of Cantilevered Ramp Injectors

激波诱燃冲压发动机作为超燃冲压发动机的一种，更加适合高超声速飞行器机体与发动机的一体化设计。为了研究其前体/进气道的燃料/空气混合特性和增强机理，本文采用地面试验方法对不同悬臂斜坡喷注器的流场特性进行了研究。研究表明，悬臂斜坡上形成的斜激波呈很强的三维效应。燃料喷注后会改变悬臂斜坡上斜激波的方向，使其与斜坡的夹角增大。悬臂斜坡的存在使流场中产生了压差，影响了气流的运动轨迹，进一步导致了流向涡的产生。后掠喷注构型和双喷口构型的混合特性更好，三角构型喷注不能形成明显的斜激波压缩波系，混合效果不佳。 Shock-induced combustion ramjet (shcramjet), as one of the scramjet engines, is more suitable for the integration design between forebody and combustion of hypersonic vehicle. In order to investigate its flowfield characteristics and mixing-enhanced mechanism of h2/air mixture for the forebody/inlet, experiment investigations are conducted to study the mixing enhancement and flow-field of the cantilevered ramp injector. The obtained results show that, it is very obvious for the three-dimensional effect of cantilevered ramp injector. The direction of oblique shock will be changed when the fuel is added, at the same time the angle of shock wave will increase. The cantilevered ramp results in the appearance of pressure gradients. The phenomenon will affect the moving tracks of flow, then leads to the generation of flow vortex. The fuel mixing performance of the sweepback and doublejet configurations are better than that of benchmark configuration. The fuel mixing performance for the triangle jet configuration is not good because the shock wave compress is not obvious for the flowfield.