Numerical Study of Combustion Efficiency and Pressure Loss in Supersonic Combustion

A numerical study on combustion phenomenon in a scramjet combustion chamber with fuel injection from different wedge angles (11, 12, 17 and 20 degrees) was done. In this combustion chamber, the Mach numbers of inflow air and hydrogen fuel are 2 and 1 respectively. The considered turbulent flow field was simulated by RANS equations in steady state form. In the present simulations, a realizable k   turbulence model was selected for turbulence simulation and also finite-rate/eddy-dissipation model was used for combustion simulation. A comparison was done between numerical and experimental results and accuracy of numerical method verified. These simulations were performed in Ansys Fluent commercial software. Results showed that with increase of wedge angle, the combustion efficiency rises from 63 to 67 percent. On the other hand, an increase in wedge angle results in stronger shock waves and also total pressure loss increases. Therefore, a compromise should be done by designer from both sides to get an efficient thrust.