Common Fuel Engines for Powered Parafoils and other Airborne Systems

"The military "Single Fuel Forward" policy under DOD Directive 4140.25 has placed high priority on the implementation of heavy fuel engines (HFE) capable of operating on logistically available kerosene based fuels. (ie: JP-5, JP-8, DF-2) Subsonic airborneapplications defined by maximum endurance and payload capacity require the HFE to have outstanding specific weight ratios below 1.5 lbs/hp as well as excellent fuel economy under .5 lbs/hp-hr. The air dropped mission scenario of the Powered Parafoilfurther complicates the HFE requirement of having to predictably start in-flight during the chute deployment at high altitude. This unattended cold start requirement is unique to the project and is the main focus of this phase I feasibilitystudy/demonstration. The proposed high-speed multi-cylinder compression ignition (CI) diesel relies on cylinder pressure/temperature to self-ignite the fuel. High altitude starting is by an innovative low cost and robust variable compression mechanism withthe assistance of conventional cold start aids. Current logistically available fuels have variable viscosity, lubricity, and cetane values that are critical factors to engine start up, peak performance, and endurance. The proposed approach incorporates aninnovative high-speed diesel injection and combustion system that is specifically designed for multi-fuel operation. The proposed effort matures a much-needed high speed, multi-fuel diesel engine technol