Studies of Flame Stability and Thermal Choking Limits in Scramjets with Hydrogen, Methane, and Ethylene Fuels

A few results on flame stability and thermal choking in a simplified model of the scramjet engine will be presented for hydrogen, methane, and ethylene fuels which are injected in crossflow to a supersonic airflow in a combustor. The parameter space investigated includes a range of air stagnation temperatures ($T_{0})$, jet-to-freestream momentum flux ratios ($J)$, and the three fuels. The analysis is done via the large-eddy simulation and within the context of the flamelet approach. Preliminary results show that hydrogen and ethylene have similar thermal chocking limits in terms of $T_{0}$ and $J$, while the methane flames are quite difficult to maintain under the current test conditions.