Combustion flow field analysis of a scramjet engine at high Mach number

A hydrogen-fueled ground testing scramjet engine operating at flight Ma 12 is numerically studied. Computation of the combustion field is carried out based on the commercial software CFD++. The basic flow structure, the spatial distribution of heat release, the combustion mode of premixed/non-premixed, and the mechanism of flame stabilization of the scramjet engine which works at Ma 12 are investigated in detail. A hydrogen-air chemistry kinetic model consisting of 7 species, 9 reaction steps is adopted in the Reynolds-Averaged Navier-Stokes simulation. The two-equation shear-stress-transport(SST) turbulence model which takes account of the wall functions is used to handle the turbulence-chemistry interactions. The results are validated by the experimentally measured wall pressure distribution with good agreement. 1) The applicability and accuracy of CFD++ in the study of compressible reactive flows under high flight Mach numbers are verified; 2)the combustion characteristics under hypersonic inflow conditions are studied; 3) the combustion efficiency, the heat release, and the combustion mode are obtained for the very high Mach number; 4)these observations offer insight into the potential for exploring the mechanisms of the combustion simulation and multi-scale combustion dynamics under hypersonic flow conditions.