Investigation of the flame stabilization mechanism of the hydrocarbon fuel in the supersonic combustor

Supersonic kerosene combustion experiments were conducted at stagnation temperature of 1085K and inlet Mach number of 2.0. High speed camera was applied to observe the shape and structure of the flame. PLIF was used to observe the distributions of kerosene and OH. Flame stabilization mechanism was analyzed with the combination of numerical and experimental results. The experimental results show that the combustion reaction occurs in the downstream of the jet stream and in the cavity region. The spread angle and the penetration height of the flame are increased with the increase of the equivalence ratio. Numerical simulations show a reasonable agreement with the experimental results. The flame stabilization mechanism analysis indicates that the kerosene fuel is mostly distributed in the region near the floor after injected into the combustor in the liquid state. Combustion product with high temperature was transported into the cavity through the interaction between the cavity shear layer and the circulation. This process provides heat and radicals to the mixture of air-kerosene in the shear layer. Hence, the flame base is able to be stabilized in the shear layer and spread to the mainstream at a constant angle.