Scramjet engines are an effective hypersonic propulsion, as they breath air at hypersonic speeds and slow it down to supersonic speeds in the combustor, allowing for effective heat addition. Liquid fueled scramjet allow for several benefits, including using the fuel in a heat exchanger as heat sink for the structure of the engine. As fuel passes the heat exchanger it will undergo endothermic reaction, producing mainly Ethylene and Methane. In this research we looked at the effect of those fuels composition on the supersonic combustion.
We designed and used a new experimental setup for scramjet combustor. A hydrogen air heater and a converging diverging nozzle are used to obtain vitiated air with a stagnation temperature of about 1600 K, stagnation pressure of 12 bar and a Mach number of 2.2 at the combustor inlet. A cavity is used for flame stabilization, and the fuel is injected through two ports – in the cavity and upstream of the cavity. The diagnostics include static pressure measurements along the walls, as well as CH chemiluminescence and shadowgraph imaging. The results presented herein show the impact of fuel flow rate and fuel composition on the flame holding, flame location, flow field, and pressure distribution in the combustor.
