Research on turbulent mixing of the bypass and core flows for air-turbo-rocket

A numerical calculation on the flow field of mixing combustion chamber without chemical reaction was carried out for hydrazine monopropellant air-turbo-rocket under uniform inlet flows. The induction and decay evolution of streamwise and normal vortices were obtained, and an analysis was made on the influence of this course on turbulent mixing efficiency of the bypass and core flows. A quantitative analysis revealed that streamwise vortices induced by a spanwise array of large scale secondary flows at trailing edge play a dominant role in the downstream mixing process of the bypass and core flows. It is preferable to employ scarfed lobed mixers with large lobe penetration rate. A preliminary analysis of turbulent mixing efficiency was also made between computational and experimental data for two mixing schemes including three kinds of lobed mixer, and results show that nonuniform inlet flow conditions have a significant impact upon turbulent mixing and combustion efficiency for small dimension air-turbo-rocket.