𝗣𝗗𝗙 | On Jul 23, , Vishal Jagadale and others published Six Stroke Engine. PDF | One of the most difficult challenges in engine technology today is the urgent need to increase engine thermal efficiency. Higher efficiencies mean less fuel. PDF | In six stroke engine, there are additional two strokes, namely another power and exhaust strokes. The engine works through harnessing wasted heat.
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Internal Combustion Engine while maintaining its prime focus on six stroke stroke the engine captures the exhausted heat from the four stroke cycle and uses. Get More Information about Six Stroke Engine PDF Download by visiting this link. Six Stroke engine, the name itself indicates a cycle of six. A Seminar On SIX STROKE ENGINE By nvrehs.infoh Abhay Chaudhari In WORKING OF VELOZETA SIX STROKE ENGINE The detailed working of .. 3) nvrehs.info (International Journal.
Being a six-stroke cycle, the camshaft speed in one third of the crankshaft speed. The combustion chambers walls are glowing when the engine is running.
Their small thickness allows heat exchange with the air-heating chamber, which is surrounding the combustion chamber. The air-heating chamber is isolated from the cylinder head to reduce thermal loss. The combustion and air-heating chambers have different compression ratio. The compression ratio is high for the heating chamber, which operates on an external cycle and is supplied solely with pure air.
On the other hand, the compression ratio is low for the combustion chamber because of effectively increased volumen, which operates on internal combustion cycle.
The combustion of all injected fuel is insured, first, by the supply of preheated pure air in the combustion chamber, then, by the glowing walls of the chamber, which acts as multiple spark plugs. In order to facilitate cold starts, the combustion chamber is fitted with a heater plug glow plug. In contrast to a diesel engine, which requires a heavy construction, this multi-fuel engine, which can also use diesel fuel, may be built in a much lighter fashion than that of a gas engine, especially in the case of all moving parts.
The currently notable six stroke engine designs in this class include two designs developed independently: However the rapid research commenced only after s. Of the piston in the same cylinder. First Category: Griffin six stroke engine: It is developed by the engineer Samuel Griffin in They used this engine mainly for electric power generation. Bajulaz six stroke engine: The Bajulaz six stroke engine is similar to a regular combustion engine in design.
There was however modifications to the cylinder head, with two supplementary fixed capacity chambers, a combustion chamber and an air preheating chamber above each cylinder. The combustion chamber receives a charge of heated air from the cylinder; the injection of fuel begins, at the same time it burns which increases the thermal efficiency compared to a burn in the cylinder.
The high pressure achieved is then released into the cylinder to work the power or expansion stroke. Meanwhile a second chamber which blankets the combustion chamber has its air content heated to a high degree by heat passing through the cylinder wall. This heated and pressurized air is then used to power an additional stroke of the 7.
Bruce Crower is actually a race car mechanic with his own workshop.
In his six-stroke engine, power is obtained in the third and sixth strokes. First four strokes of this engine are similar to a normal four stroke engine and power is delivered in the third stroke. Just prior to the fifth stroke, water is injected directly into the heated cylinder via the converted diesel engine's fuel injector pump. The injected water absorbs the heat produced in the cylinder and converts into superheated steam, which causes the water to expand to times its volume and forces the piston down for an additional stroke i.
The phase change from liquid to steam removes the excess heat of the engine. As a substantial portion of engine heat now leaves the cylinder in the form of steam, no cooling system radiator is required. Energy that is dissipated in conventional arrangements by the radiation cooling system has been converted into additional power strokes. In Crower's prototype, the water for the steam cycle is consumed at a rate approximately equal to that of the fuel, but in production models, the steam will be recaptured in a condenser for re-use.
Second category: Beare Head six stroke engine: Malcolm Beare year-old Australian wheat farmer is the inventor of this six stroke engine. Actually the name six stroke engines was introduced by Malcolm Beare. Beare created an innovative hybrid engine, combining two-strokes in the top end with a four-stroke above the middle portion.
So by adding this four plus two equals six, he derived the name six stroke engines. Below the cylinder head gasket, everything is conventional, in his design. So one main advantage is that the Beare concept can be transplanted to existing engines without any redesigning or retooling the bottom end and cylinder. But the cylinder head and its poppet valves get thrown away in this design. To replace the camshaft and valves, Beare used a short-stroke upper crankshaft complete with piston, which is driven at half engine speed through the chain drive from the engine.
This piston moves against the main piston in the cylinder and if the bottom piston comes four times upwards, upper piston will come downwards twice. The compression of charge takes place in between these two pistons. Much higher compression ratios can be obtained in this engine. Malcolm used on his first six-stroke, based on a Honda XL farm bike. Charge pump engine: The piston charger charges the main cylinder and simultaneously regulates the inlet and the outlet aperture leading to no loss of air and fuel in the exhaust.
In the main cylinder, combustion takes place every turn as in a two-stroke engine and lubrication as in a four- stroke engine. Fuel injection can take place in the piston charger, in the gas transfer channel or in the combustion chamber.
It is also possible to charge two working cylinders with one piston charger. The combination of compact design for the combustion chamber together with no loss of air and fuel is claimed to give the engine more torque, more power and better fuel consumption.
The benefit of less moving parts and design is claimed to lead to lower manufacturing costs. Good for hybrid technology and stationary engines. The engine is claimed to be suited to alternative fuels since there is no corrosion or deposits left on valves.
The six strokes are: This would be so if all other factors remain constant. Advancing the upper Valve Timing: The effect is to open the exhaust port earlier, reduce the amount of valve overlap and close the intake port earlier.
Opening the exhaust port earlier means that the expansion stroke is effectively shortened and less energy is extracted. Reducing the amount of overlap does not allow enough time for intake to clear the combustion chamber and the exhaust extraction effect is reduced.
The earlier intake port closing reduces charge filling and volumetric efficiency. Combustion chamber volume: It is effectively increased thus lowering compression ratio.
The rate of acceleration of expansion is faster in the earlier periods, contrary to the ideal of a constant volume during combustion. Use of the Rankine Cycle , turbocharging and thermoelectric generation can be very useful as a waste heat recovery system.
Though these systems are used more frequently some issues, like their low efficiency at lower heat supply rates and high pumping losses, remain a cause of concern. This can be done using some type of air compression device known as a supercharger , which can be powered by the engine crankshaft. Supercharging increases the power output limits of an internal combustion engine relative to its displacement.
Most commonly, the supercharger is always running, but there have been designs that allow it to be cut out or run at varying speeds relative to engine speed. Mechanically driven supercharging has the disadvantage that some of the output power is used to drive the supercharger, while power is wasted in the high pressure exhaust, as the air has been compressed twice and then gains more potential volume in the combustion but it is only expanded in one stage.
Turbocharging[ edit ] A turbocharger is a supercharger that is driven by the engine's exhaust gases, by means of a turbine. A turbocharger is incorporated into the exhaust system of a vehicle to make use of the expelled exhaust. It consists of a two piece, high-speed turbine assembly with one side that compresses the intake air, and the other side that is powered by the exhaust gas outflow.
When idling, and at low-to-moderate speeds, the turbine produces little power from the small exhaust volume, the turbocharger has little effect and the engine operates nearly in a naturally aspirated manner. When much more power output is required, the engine speed and throttle opening are increased until the exhaust gases are sufficient to 'spool up' the turbocharger's turbine to start compressing much more air than normal into the intake manifold.
Thus, additional power and speed is expelled through the function of this turbine. Turbocharging allows for more efficient engine operation because it is driven by exhaust pressure that would otherwise be mostly wasted, but there is a design limitation known as turbo lag.
The increased engine power is not immediately available due to the need to sharply increase engine RPM, to build up pressure and to spin up the turbo, before the turbo starts to do any useful air compression. The increased intake volume causes increased exhaust and spins the turbo faster, and so forth until steady high power operation is reached. Another difficulty is that the higher exhaust pressure causes the exhaust gas to transfer more of its heat to the mechanical parts of the engine.
Rod and piston-to-stroke ratio[ edit ] The rod-to-stroke ratio is the ratio of the length of the connecting rod to the length of the piston stroke.