The Duke Engine is an advanced internal combustion engine delivering high thermodynamic efficiency, complete fuel flexibility, (runs on any suitable spark ignition fuel), negligible 1st and 2nd order vibration with huge weight and size savings, which is ideal in general aviation or experimental aircraft.
This engine is the world's only viable axial, 4 stroke, spark ignited piston engine. It is lightweight, small, valveless, vibration-free, has very high power density, and runs on most fuels, including kerosene/jet fuel. The Duke engine is a great fit for aerospace applications, including ultralight, experimental and UAV platforms.
The Duke engine is in advanced stages of development, with prototype engines operational. The 5 cylinder, 4-stroke internal combustion engine platform offers numerous benefits in aerospace applications:
Cooling is achieved with conventional water jackets around the cylinders and ported areas. Seals around concentric flow passages allow the coolant to enter and leave the rotating cylinder group. The coolant is then circulated in a conventional manner through radiators mounted on the airframe, using a pump.
The absence of hot valves in the favourably-shaped combustion chamber allows high compression ratios for efficient operation on low octane fuels. Current engines operate on 91 octane gasoline detonation free at compression ratios above 12.5:1.
Development will allow operation on all appropriate fuels, including ethanol/methanol and blends, bio-ethanol, LPG, CNG, hydrogen, kerosene and diesel. Spark ignited Duke engines are currently successfully running on 91 octane gasoline and kerosene/jet-A1.
The much lower part and component count (only 3 sets of spark plugs, injectors and ports for 5 cylinders with no valve train), coupled with ease of repair and maintenance and potentially lower production costs, offer potential for savings in manufacturing and operation. While the Duke uses existing materials and manufacturing processes in its construction, there is considerable scope for the use of light weight materials as appropriate.
Duke Aircraft Engine #1 is a 2.0 Ltr – 3300 rpm with 103 hp @ 3300 rpm and weighs 101 lbs (no gearbox required). Size: Length: 17.3 in x Diameter: 11.6 in.
Duke Aircraft Engine #2 is also 2.0 Ltr but at 6250 rpm with 180 hp @ 6250 rpm with equal weight: 101 lbs (needs a gearbox) Size: Length: 17.3 in x Diameter: 11.6 in.
Text used with permission.