An Advanced Endothermic Fuel System for Hypersonic Propulsion

ABSTRACT:The development of weapons that can travel at hypersonic speeds is becoming a high priority to the US Air Force.A key technology needed for the continued development of these propulsion systems is the ability to cool the combustor by flowing fuel through channels machined in the walls.Currently, the cooling capacity of kerosene-based fuels is relatively low even with endothermic cracking reactions, and this limits the Mach number that can be achieved.Moreover, increasing the fuel cooling capacity by allowing the fuel to reach higher temperatures is not feasible because coke formation could lead to heat exchanger failure.Therefore, there is a strong need to develop new endothermic fuels that can deliver substantially higher heat sink capacities.In the Phase I project Reaction Systems identified a fuel and catalyzed endothermic reaction that produced a high chemical endotherm at high temperature with no measurable coke deposition and showed that high heat fluxes can be obtained in the catalyzed heat exchanger.The goal of the Phase II project is to measure and refine the design of the fuel/catalyst heat exchanger performance under more representative conditions and demonstrate that the system can be used effectively in hypersonic vehicles.BENEFIT:The US Air Force recognizes that developing weapons that can cover 600 nautical miles in 10 minutes or less (speeds of Mach 5 and greater) is essential to its war fighting capabilities and that reliable scramjet propulsion systems are needed in support this objective.A critical technology required in the continued development of scramjets is obtaining the required cooling in the combustor.The endothermic fuel system being developed in this Phase II program provides higher heat sink capacity to sustain higher flight Mach numbers while also providing improved ignition and flameholding properties compared to JP-7.This technology can be used to develop a new class of weapons and aircraft with global reach and game-changing capabilities that include precise targeting, rapid long range response, and better survivability against ballistic missile and space defenses.Initially, the technology developed in this project will be particularly well-suited for the new Air Force High Speed Strike Weapon (HSSW) missile program, and this will probably be the first product to incorporate this new fuel system.There are also additional research programs being started, such as a new Navy sea-launched hypersonic missile study and Lockheed-Martins SR-72an updated SR-71 for a Mach 6 dual ISR (Intelligence Surveillance Reconnaissance) and Strike aircraft that could also lead to the implementation of our high performance endothermic fuel blend.