Flow-Field Analysis of a Typical Hydrogen-Fueled Dual-Mode Scramjet Combustor

Abstract

As one of the most promising propulsive systems for future hypersonic vehicles, the hydrogen-fueled dual-mode scramjet combustor has drawn the attention of an ever increasing number of researchers. The two-dimensional coupled implicit NS equations, the standard $k-\epsilon$ turbulence model, and the finite-rate/eddy-dissipation reaction model have been applied to numerically simulate the flow field of the dual-mode scramjet combustor, including the conditions of engine ignition and cold flow. The effect of the injection pressure and temperature on mode transition, and the movement of the shock-wave train, has been discussed. At the same time, the influence of the injection modes, namely, the transverse and horizontal, on the flow field of the combustor has been investigated. The obtained results show that the mode transition can be carried out by increasing the injection pressure and decreasing the injection temperature simultaneously. However, when the injection pressure is too high, the shock-wave train is pushed out of the isolator toward the entrance, and this causes inlet unstart. It has been found that the effect of the injection temperature on mode transition is smaller than that of the injection pressure. It is not easy to achieve mode transition when the fuel is injected horizontally into the airflow, and the combustion efficiency is lower than when the fuel is injected transversely.