Performance Improvement of DLR Scramjet Combustor Using Modified Strut Injector

Abstract

Flow field organization significantly influences the performance criterion of a scramjet combustor. Recently, DLR scramjet combustor with strut injector has been mostly used to alter the flow field. Researchers have used innovative strut injectors to enhance the performance of the DLR scramjet combustor. However, the effect of utilizing a strut with both parallel and normal injections of air and fuel in the DLR scramjet combustor has not been investigated till date. Hence, in this study, the DLR combustor is numerically investigated using a modified strut injector with both parallel and normal injections of air and fuel. The 2D numerical solver is validated with the experimental results having a maximum deviation of 7.3%. The analysis shows that the combustors with modified strut injectors produce better turbulence mixing compared to the DLR combustor, resulting in higher combustion performance. The modified strut combustors, i.e., CMSI-1, CMSI-2, and CMSI-3 produced a combustion efficiency of 76%, 79%, and 81%. In contrast, the maximum combustion efficiency produced by the DLR combustor is 50%. This improvement in the combustion performance of the combustors with modified strut injectors resulted in higher thrust force than the DLR combustor. The thrust force produced by CMSI-1, CMSI-2 and CMSI-3 are 3160 Pa.m², 3200 Pa.m² and 3216 Pa.m², respectively. Finally, it has been found that the CMSI-3 has produced the maximum combustion efficiency and better thrust force among all the scramjet combustor models considered in the study.