EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE DENSITY FIELD IN A SUPERSONIC COMBUSTOR WITH BACKWARD-FACING STEPS

Experimental and numerical data on the flow structure in supersonic co mbustion chambers are important for the design of high performance SCR AM jet propulsion systems. This paper concentrates on the investigatio n of the non-reactive flow field in a supersonic multistep combustor w ith backward facing steps and fuel injection. The influence of the inj ected fuel on the flow field in a supersonic combustion chamber was in vestigated using non-intrusive diagnostic methods. Special interest fo cused on its impact on the reattachment length of the shear layer and the structure of the oblique shock wave system. Eddies, that are induc ed by local velocity gradients in the flow field, are able to enhance the mixing process in supersonic combustion chambers [1]. These gradie nts are caused by shock waves, expansion fans and free shear layers an d induce local density gradients. An Euler code was developed to compu te the density and the local Mach number distribution in the flow fiel d in order to get insight into the flow structures that could be seen in the experiments.