This program will conduct analytical studies to demonstrate how to convert the AR-741, rotary engine, to run on heavy fuel. Specifically, CFD modeling will be used to show how direct injection/stratified charge can be employed to convert this engine to heavy fuel. The direct injection will avoid predetonation, while the stratified charge or layering of the fuel air mixture will be investigated for a "lean burn" characteristic to achieve the best fuel economy. Further, the spray pattern will show a rich fuel mixture at the point of ignition for sufficient starting ease. The effects of turbocharging will also be modeled to achieve the desired SFC of 0.35. Thermodynamic cycle analysis will be used as a first order attempt to show the benefits of turbocharging and increased compression ratio on SFC. Computational Fluid Dynamics (CFD) will be used for the combustion design; showing the optimum location for the fuel injectors/igniters, spray pattern, mixing, and the corresponding combustion process. CFD will be used to determine optimal rotor pocket geometery and the investigation of the benefits for "split" combustion chamber operation. Lastly, we believe that in order to achieve the desires SFC of 0.35 lbs/HP-hr turbocharging will be a neccessity.
Keywords: Direct Injection, Stratified Charge, Rotary Engine, Turbulence, Heavy Fuel, Unmanned Aerial Vehicles, Combustion, Computational Fluid Dynamics
