1 INTRODUCTIONDuke Engines are in an advanced stage of developing a unique high-speed, valve-less 5 cylinders, 3 injector axial internal combustion engine with zero first-order vibration, significantly reduced size and weight, very high power density and the ability to run on multiple fuels and biofuels. The Duke engine is suited for many uses including marine, military automobile, light aircraft and range extender applications. The Duke engine’s 5 cylinder, 3 liter, 4-stroke internal combustion engine platform with its unique axial arrangement is already in its 3rd generation. In comparisons made to conventional IC engines with similar displacement, the Duke engine was found to be up to 19% lighter and up to 36% smaller. The Duke’s notating reciprocator leads to very low angles of con rod articulation resulting in a near sinusoidal reciprocating motion. This combined with the counter-rotating cylinder group and crankshaft in the Duke engine delivers near perfect mechanical balance resulting in a very low vibration engine. Axial engines, including barrel engines, Wobble-plate engines and cam engines, are a type of reciprocating engine with pistons arranged around an output shaft with their axes parallel to the shaft. The key advantage of the axial design is that the cylinders are arranged in parallel around the output shaft rather than at 90 degrees as in crankshaft engines. As a result it is a very compact, cylindrical engine, allowing variation in compression ratio of the engine while running. In a Wobble-plate engine the piston rods stay parallel with the shaft, and piston side-forces that cause excessive wear can be eliminated almost completely. The small-end bearing of a traditional connecting rod, one of the most problematic bearings in a traditional engine, is eliminated. An alternate design, the Rand cam engine, replaces the plate with a sine-shaped cam. The Duke engine's lower component count (only 3 sets of injectors and ports for 5 cylinders with no valve train). The absence of hot valves in the favorably shaped combustion chamber allows high compression ratios for efficient operation on low octane fuels. . make for savings in manufacturing and operation. The current engine can be run on any suitable spark ignition fuel.0L torque output of 339Nm / 250ft/lbs. With only 3 exhaust headers for 5 cylinders there is a low surface area for heat loss prior to any catalytic converter. especially at higher power and speed. 160kW power output is competitive with conventional SI engines of equivalent • displacement and is currently achieved at only 4500 rpm. 3 Significance of current gasoline performance status: • • 11.2 The Duke Engine features The Duke's unique counter rotation. allowing a 20% higher output to be achieved at any given speed. addresses previous limitations that have prevented the commercialization of axial piston engines to date. 3 dimensional. V3i gasoline performance reported is below its real potential due to the lower Jet A1 compression ratio used and interim precautionary limit of 4500 rpm in this test phase (design target 6000 rpm).8 Bar BMEP is competitive with conventional SI engines. is above that typically achieved by comparable conventional engines . almost vibration free motion and the innovative methodology employed to achieve this. offering a potential catalyst light-off benefit. 3.due to pistons reciprocating at 120% of output • speed. coupled with potentially lower production costs. a swash-plate rotates but instead the disk is mounted at an oblique angle.1 Centrifugal forces in an axial layout The centrifugal forces in the Duke engine have been thoroughly analyzed. . It should be considered that the cylinder block rotates at a fraction of crankshaft speed and as a result Duke radial inertial piston forces have been shown to be lower than the side forces created by the conrods angle in a conventional engine. Therefore we achieve a much more complete burn than a rotary. This motion can be simulated by placing a Compact Disc on a ball bearing at its center and pressing down at progressive places around its circumference. which causes its edge to appear to describe a path that oscillates along the shaft's length as observed from a non-rotating point of view away from the shaft. The device has many similarities to the cam.3. Internal combustion engines and sterling engines have been built using this mechanism. The Wobble-plate engine uses a Wobble-plate in place of a crankshaft to translate the motion of a piston into rotary motion. in that the pistons press down on the plate in sequence. The apparent linear motion can be turned into an actual linear motion by means of a follower that does not turn with the Wobble-plate but presses against one of the disk's two surfaces near its circumference.There is currently some oil required for the seals to work and this can add to the emissions. however our consumption is far less than that required for a 2-stroke or rotary.2 Emissions Like the Winkle rotary combustion chamber is unencumbered with valves and such like. The difference is that while a wobble plate nutate. forcing it to nutate around its center. However unlike the rotary we approach a near optimal chamber shape far closer to a conventional 4-stroke engine. Charge motion development will further improve our combustion efficiency to approach that of a conventional 4-stroke. 3. A wobble-plate is similar to a swashplate. The greater the disk's angle to the shaft. the more pronounced is this apparent linear motion. 4 Working Principles It works on basic principle of Wobble-plate. The axial piston pump drives a series of pistons aligned coaxially with a shaft through a Wobble-plate to pump a fluid. 2 Compression : Fig. Charge compressed The charges then compressed before the cylinder exposed to spark plug. Charge intake Instead of using complicated valve system slide pass forth and spark plug are mounted on stationary head ring as the cylinder slide passes the inlet the fuel and air charge let in.1. .2. 4.4.1.1 Working of cycles 4.1.1Intake: Fig. 1.4. Ignition by Spark The charge burns and driving the piston down in power stroke.4.3.4 Exhaust Fig. Exhaust of burned charge The piston then rises again ejecting the combustion gases through exhaust port to complete 4 stroke cycle.1. . 4.3 Ignition Fig. 2 Working of wobble plate: A wobble plate does not go round. but can be more of a spider. and clearly if it did go round would tie these rods in knots. Fig. it is mounted on the Z-shaped crankshaft by a bearing. Position of wobble plate . it does intoned to be a plate as such. It is articulated to the connecting rods by ball-joints.4.5. The Duke Engine is generally well suited to many applications of 40kW or greater. The output shaft. being equal to conventional engines in their fully developed state. • Low weight. • • • • Marine Military automobile Light aircraft Range extender applications 7 Advantages: • Installation in small cowlings with lower drag. 6 Applications As well as automotive applications the Duke Engine lends itself well to Marine. This result made it competitive with modern high end automotive engines operating a similar combustion cycle (gasoline. port injected. being 'geared down' to 5/6 of the piston reciprocating speed. . • Small package size. Aircraft and Generator/Utility Range Extender options.It should be recognized that the Duke engine at an early and non optimized condition. • Near perfect mechanical balance for very low vibration. spark ignition). allows the 'engine-out' torque to be higher and maximum torque to be developed at lower speeds. These tests were conducted. offers the very real prospect for a developed Duke engine to improve substantially in comparison to conventional engines.5 Duke Fuel efficiency .Brake Specific Fuel Consumption (BSFC): A Duke engine was tested with BSFC of 255g/kWhr in the load/speed region near maximum output. Exhaust temperature at part-load is high compared to conventional engines – this might prove to be an advantage for catalyst light-off in automotive applications… . • Partial cancellation of gyroscopic effects from slow speed counter rotation of cylinder group. • Simplicity of design – 3 injectors & 3 manifold connections for 5 cylinder engine.• Direct drive low-power or geared high-power options. • No cam drive train or valves. • Suitable for 50hp to 350+ hp 8 Conclusions: • • Part-load fuel economy is comparable with modern conventional engines Full-load performance is comparable with modern conventional engines without performance enhancing technologies such as cam phasing and switchable intake systems • • Motored engine friction falls within the range of current conventional engines.. • Multi fuel options. Automotive gasoline with low octane requirements. Compatible with 100LL avgas. • Low parts count. • Multi-point spark ignition simply achieved. com/ http://www.dukeengines.com/user/DukeEngines http://www.wikipedia.youtube.com/MUSEUM/POWER/unusualICeng/axial-ICeng/axial- • IC.com/duke-engines-5-cylinder-4-stroke-3-injector-valveless-axial- • engine/ .org/wiki/Axial_engine http://thekneeslider.htm#tech http://en.douglas-self.9 References • • • http://www.