Experimental investigations on the self-ignition of a thermally decomposed endothermic fuel in hot supersonic air flow in the MPP-LAERTE combustion test bench

Abstract

As hypersonic propulsion with scramjets leads to excessive heating of the combustor materials, active cooling is required. An interesting way is the thermal cracking of heavy hydrocarbon fuels (endothermic reactions) along the walls of the combustor before injection. The present work takes part in a French hypersonic program, and especially deals with the combustion of such a thermally decomposed fuel in the LAERTE supersonic test bench. For this, the MPP device has been coupled to the wall injector of the LAERTE facility, delivering less than 5 g.s of cracked fuel under supercritical conditions (temperature up to 970 K and pressure over 30 bar). Shadowscopy of the fuel entry in the combustor and imaging of its ignition in the supersonic hot air flow (freestream temperature of 1181 K) have been achieved.