Soluble Catalysts to Improve Jet Fuel Combustion and Fuel Heat Sink Capacity

Rocket Based Combined Cycle (RBCC) propulsion systems likely will be used to launch next-generation space vehicles. However, in the scramjet portion of the cycle, it is difficult to maintain stable combustion because of the high air velocity and short combustor residence times. In addition, the overall heat load in a scramjet engine exceeds the cooling capacity that can be provided from the sensible heating of hydrocarbon-based jet fuels therefore the fuel must undergo endothermic cracking reactions to augment its heat sink capacity before it reaches the combustor. However, additives may significantly improve combustion and increase endothermic cracking reactions. The additive will function by reducing the activation energy of both oxidation and cracking reaction thereby increasing the rates substantially. Moreover, the products of the cracking reaction which occurs upstream of the combustor will provide additional combustion stabilization. Thus in this Phase I STTR Project TDA Research, Inc. will synthesize and test several additives that will reduce ignition delay times when injected directly into a combustor and increase the rate of cracking when mixed with the fuel upstream of the combustor. Finally, we will also obtain fundamental structural and mechanistic information on the additive using state of the art analytical equipment.