CFD analysis of an ethylene-fueled intake-injection shock-induced-combustion scramjet configuration

A computational analysis of ethylene combustion in scramjet engine applications has been performed. The capability of simplified chemical reaction mechanisms to accurately calculate ignition delay and heat release has been assessed. The 10 step Jachimowski ethylene combustion model was found to over predict ignition delay by almost an order of magnitude. Using this mechanism, CFD calculations have been made of a threedimensional geometry representing a potential configuration for the Australian developed HyShot scramjet. The free stream conditions are those of shock tunnel conditions with equivalent flight speed of Mach 9.4 at 35 km altitude. Within the 3D flow field the Jachimowski reaction mechanism calculated extremely limited combustion with one percent of injected fuel consumed. An increase of the scale of the scramjet by one order of magnitude enhanced the extent of combustion, but not sufficiently to produce any significant pressure rise since it was found that the fuel injection was not delivering the ethylene to the region where it was most likely to bur