Combustion characteristics of scramjet combustor

Based on a kind of kerosene-fueled scramjet combustor with low internal drag slick configuration, numerical simulation based on finite difference method was performed for its supersonic flowfield. The inviscid flux was discretized by WENO (weighted essentially non-oscillatory) scheme, and the turbulent model was SST (shear stress transport) k-ω model. The single step chemical reaction mechanism was adopted for kerosene (C₁₂H₂₃). Predicted value of the wall static pressure along the side wall of the combustor is consistent with previously reported test data, indicating the present algorithm is applicable for the simulation of supersonic combustion in kerosene-fueled combustor. The effects of inflow static temperature, fuel/air equivalence ratio and jet location on the kerosene supersonic flow and combustion in this combustor were discussed. Results show that combustion is concentrated near the wall boundary layer at the side of the jet nozzle, and the ignition location is very sensitive to the local static temperature. The lower inflow static temperature, fuel/air equivalence ratio and the larger combustor expansion angle mean the less combustion efficiency and combustion performance, and the ignition location moves towards the combustor exit, with the shock cluster inspired by combustion disappearing. Staggered arrangement of the jet nozzles on the upper and lower walls of the combustor can improve the combustion efficiency. Therefore, preliminary critical boundary conditions are obtained to achieve ignition in the slick kerosene-fueled combustor.