Computational study of hydrogen and air co-flow jets mixing in dual-combustor ramjet in presence of ramp shock generator

Abstract

Flame stabilization distribution and efficient fuel mixing are highly significant in the performance of ramjet engine. In this paper, numerical studies are done to investigate the supersonic combustion of hydrogen and air co-flow in presence of the ramp edge. In this study, flame maintenance and combustion formation in a dual-combustion ramjet engine are fully investigated. The primary emphasis of this work is to disclose the impact of produced shocks due to the existence of ramp edge on the structure of fuel and air-jet immediately downstream of injector. The shock interactions of two different angles (10 deg and 30 deg) of the ramp edge are investigated. Favre-averaged conservation equations are considered for the simulation of compressible flows inside the combustor. Various mechanisms expressing the flame spreading characteristics are also examined. Depending on the angle of the ramp edge, the produced shock waves influence on size and strength of vortices. Our findings also show that high angles of ramp edge augment the fluctuation of the vortices by the splitter and consequently, fuel mixing enhances in the combustion chamber of ramjet engine. Our findings also confirm that the similar jet pressure would be more effective on the vortex production downstream of the splitter. The application of ramp edge with angle of 30 deg would increase average momentum thickness of the mixing layer up to 55%.