Mixing performance of transverse hydrogen/air multi-jet through coaxial injector arrays in supersonic crossflow

Abstract Increasing the fuel mixing performance substantially improves the overall performance of the scramjet engine for a long-distance flight. In this paper, the influence of coaxial injector arrays of hydrogen/air multi-jet on the mixing performance of the fuel in supersonic crossflow is fully investigated. Our main goal is to examine the impacts of air and fuel coaxial injector on fuel distribution and penetration downstream of injectors in different operating conditions. In this study, fuel and air are simultaneously injected through coaxial multi-jet at sonic condition while of free-stream Mach number is 4. Computational Fluid Dynamic is applied for simulation of the transverse coaxial jet at supersonic crossflow. The effect of jet diameter with the same mass flow rate of air and hydrogen on fuel mixing is also investigated. The mixing efficiency of different jet spaces and pressures is also examined to obtain an optimum jet arrangement in the combustor chamber. Our study shows that the injection of the coaxial air/hydrogen jet noticeably improves mixing downstream by augmentation of fuel interaction with an air jet. Our results also show that fuel jet space of 7 Dj offers maximum fuel mixing by the formation of multi vortices with uniform strength.