Numerical simulation of secondary combustion of hydrogen injected from preburner into supersonic airflow

The combustion of preburned hydrogen in the supersonic wake flowfield behind a thick base was studied numerically. The Navier-Stokes equations in conjunction with an algebraic turbulence model as well as the full hydrogen chemistry are solved by a lower-upper successive Gauss-Seidel total variation diminishing scheme. First, results of the present numerical simulation are compared with previous experimental results for a nonreacting wake flow behind a base. Then, ignition and flame holding of preburned hydrogen are examined. It is shown that use of a preburner is a reliable method for self-ignition and combustion of hydrogen in a low-temperature supersonic airflow. Furthermore, the mechanism of combustion, the flame structure, and the effects of the preburner equivalance ratio and pressure and the supersonic airflow temperature on flame holding and combustion efficiency were investigated.