Abstract The mixed augmentation performance between secondary fuel jet and uneven supersonic inflow is a significant evaluation index of the rocket-based combined cycle engine. In this study, the effects of the secondary fuel jet on the flow field structure and mixing enhancement performance are discussed by changing both the secondary fuel jet angle and spacing of multiple rows of jet holes. The three-dimensional coupled implicit Reynolds averaged Navier-Stokes equations, SST k - ω turbulence model, and eddy dissipation concept (EDC) reaction model were adopted to evaluate the flow field structure with a sonic hydrogen jet. It is indicated that the 135° fuel jet has the largest penetration depth value, followed by the 90° fuel jet, whereas the 45° fuel jet has the smallest penetration depth value. However, the 45° fuel jet possesses the best mixing performance, it easily induces a pair of downstream counter-rotating vortex, and the oblique torque is further generated to aggravate the tearing ability to the jet. The three jet holes induce a stronger shock wave and form a larger barrier under the 90° jet. Additionally, when the spacing between the multiple rows of jet holes reduces, penetration depth is easily created. Further, when the spacing of the three rows of jet holes is larger, the fluctuation of the mixing coefficient increases.

中文翻译：

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火箭基联合循环发动机混合增强性能的二次燃料喷射策略

摘要 二次燃料射流与超音速不均匀进气混合增强性能是火箭基联合循环发动机的重要评价指标。本研究通过改变二次燃料射流角度和多排喷孔间距，探讨二次燃料射流对流场结构和混合增强性能的影响。采用三维耦合隐式雷诺平均Navier-Stokes方程、SST k-ω湍流模型和涡耗散概念（EDC）反应模型对声速氢射流流场结构进行评估。表明135°燃油射流的穿透深度值最大，其次是90°燃油射流，而45°燃油射流的穿透深度值最小。然而，45°燃油喷射具有最佳混合性能，容易在下游产生一对反向旋转涡流，进一步产生斜扭矩，加剧喷射的撕裂能力。三个喷气孔引发更强的冲击波，在90°喷气下形成更大的屏障。此外，当多排喷射孔之间的间距减小时，很容易产生穿透深度。进一步地，当三排喷孔的间距较大时，混合系数的波动会增大。当多排喷射孔之间的间距减小时，很容易产生穿透深度。进一步地，当三排喷孔的间距较大时，混合系数的波动会增大。当多排喷射孔之间的间距减小时，很容易产生穿透深度。进一步地，当三排喷孔的间距较大时，混合系数的波动会增大。