NUMERICAL-SIMULATION OF SECONDARY COMBUSTION OF HYDROGEN INJECTED FROM PREBURNER INTO SUPERSONIC AIR-FLOW

The combustion of preburned hydrogen in the supersonic wake flowfield behind a thick base was studied numerically. The Navier-Stokes equatio ns in conjunction with an algebraic turbulence model as well as the fu ll hydrogen chemistry are solved by a lower-upper successive Gauss-Sei del total variation diminishing scheme. First, results of the present numerical simulation are compared with previous experimental results f or a nonreacting wake flow behind a base. Then, ignition and flame hol ding of preburned hydrogen are examined, It is shown that use of a pre burner is a reliable method for self-ignition and combustion of hydrog en in a low-temperature supersonic airflow Furthermore, the mechanism of combustion, the flame structure, and the effects of the preburner e quivalance ratio and pressure and the supersonic airflow temperature o n flame holding and combustion efficiency were investigated.