Numerical investigation on the mixing and combustion in supersonic ejecting flow of RBCC

3D mixing and reacting flows of five RBCC configurations in ejecting mode were investigated with numerical techniques and newly established mixing degree model. The effects of secondary combustion and geometry configuration on ejecting and mixing were analyzed in detail. It was concluded that: 1)The geometry configuration of RBCC affects the mixing process of rocket ejector mode greatly, in which the geometry structure of primary nozzle mainly determines the upstream mixing, while the geometry of flow path determines the downstream. 2) The secondary combustion can promote the thrust, but for different configuration, the promotion magnitude is different. 3) The key elements of thrust augmentation obtained by the improved configuration are higher mixing degree, positive pressure state and higher combustion efficiency.