Numerical and experimental studies of injection modeling for supersonic flame-holding

The effects of injection modeling on the combustion of hydrogen in a supersonic airflow are considered here using both numerical and experimental approaches. Two types of injection, single and double from the base of a strut, are analyzed in depth. The solutions to the governing equations of the numerical simulation including Navier-Stokes (N-S) equations, turbulence model, and finite full chemistry are brought in using a high-order numerical scheme. In particular, the laser-induced-fluorescence (LIF) method is effectively used for the OH radical recording. The flame structures of two different injection models are simulated separately using both numerical and experimental techniques for comparison. As a result of changes in the flowfield as well as mixing phenomenon, the flame structure of the double-slit injection model is significantly different from the one for the single injection. By increasing the slit interval of the double-slit injection, the model can face the blowout when d > 8 mm. Furthermore, an increase in the slit width can also affect the flowfield of the wake significantly so that the combustion zone will expand downstream.