CFD numerical simulation was carried out for cold flow and combustion flow of the Hyshot scramjet to test the accuracy of turbulence flow model and turbulent combustion model. For cold flow

the predicted wall pressure profile was in accurate agreement with experimental data and the simulation result was insensitive to turbulence flow model choice. However

the predicted field of turbulence variables (turbulence kinetic energy and its dissipation rate) in cold flow is strongly influenced by turbulence flow model choice; these turbulence variables affect the mixing of hydrogen fuel and air and the subsequent combustion. Indeed

the simulation of combustion flow showed strong dependence on turbulence flow model and turbulent combustion model choice. The best combustion simulation result with SST k-ω turbulence flow model and EDM turbulence combustion model has good agreement with experimental wall pressure data

but the pressure peak location is slightly deviated. The effect of fuel injection angle was also simulated. Eight injection angles of hydrogen fuel were tested and it was shown that the scramjet has best fuel/air mixing and combustion efficiency with injection angles of 99° and 114°.