Flow structure and fuel mixing of hydrogen multi-jets in existence of upstream divergent ramp at supersonic combustion chamber

The enhancement of fuel distribution within the combustion chamber significantly affects the productivity of scramjet engine. In current effort, comprehensive efforts have been performed to investigate the impact of the upstream ramp on the diffusion and mixing of four hydrogen multi-jets at Ma>1. Current study employed CFD to model compressible flow of air and fuel in presence of an upstream ramp with two slopes of 20 and 30. The purpose of current study is to examine fuel jet and air stream interaction when an angled divergent ramp is located nearby injectors. The three-dimensional feature of the jet in these two configurations are fully investigated and mixing performance and jet circulations are compared to reveal important factors on fuel penetration in the combustion chamber. Our findings showed that presence of an upstream ramp sufficiently improves the fuel mixing downstream of injectors. The mixing performance analysis also shows that increasing the ramp slope to 30° could increase fuel mixing around 80% far downstream.