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Group Presentation
ONSIX STROKE ENGINE
INTRODUCTIONThe six-stroke engine is a type of internal combustion engine based on the four-stroke engine.
First developed in early 1990’s
Advancement is the Duel fuel six stroke diesel engine
More efficient & reduce emissions.
Approaches for six stroke engine designFirst approach
There is two additional strokes by the main piston as fifth and sixth strokeSecond approach
It uses a second opposed piston which moves at half the cyclical rate of the main piston
SIX STROKE ENGINEFIRST APPROACH
Griffin six stroke engine
Bajulaz six stroke engine
Crower six stroke engine
Velozeta six stroke engine
SECOND APPROACHBeare head six stroke engine
Piston charger engine
TYPES
FIRST APPROACH SIX STROKE
ENGINE
In a six-stroke engine prototyped in the United States by Bruce Crower, water is injected into the cylinder after the exhaust stroke and is instantly turned to steam, which expands and forces the piston down for an additional power stroke. Thus, waste heat that requires an air or water cooling system to discharge in most engines is captured and put to use driving the piston.Crower estimated that his design would reduce fuel consumption by 40% by generating the same power output at a lower RPM. The weight associated with a cooling system could be eliminated
CROWER ENGINE
but that would be balanced by a need for a water tank in addition to the normal fuel tank.
In a Velozeta engine, fresh air is injected into the cylinder during the exhaust stroke, which expands by heat and therefore forces the piston down for an additional stroke. The valve overlaps have been removed and the two additional strokes using air injection provide for better gas scavenging. The engine seems to show 40% reduction in fuel consumption and dramatic reduction in air pollution.Its specific power is slightly less than that of a four-stroke gasoline engine. The engine can run on a variety of fuels, ranging from gasoline and diesel fuel to LPG. An altered engine shows a 65% reduction in carbon monoxide pollution when compared with the four-stroke engine from which it was developed
VELOZETA ENGINE
The Bajulaz six-stroke engine is similar to a regular combustion engine in design. There are, 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 an isochoric (constant-volume) burn which increases the thermal efficiency compared to a burn in the cylinder.
BAJULAZ ENGINE
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 piston.The claimed advantages of the engine include reduction in fuel consumption by at least 40%, two expansion strokes in six strokes, multi-fuel usage capability, and a dramatic reduction in pollution.
BAJULAZ SIX STROKE ENGINE
1. Intake valve2. Heating chamber valve3. Combustion chamber valve4. Exhaust valve5. Cylinder 6. Combustion chamber7. Air heating chamber8. Wall of combustion chamber9. Fuel injector 10.Heater plug
STROKE 1Intake of pure air in the cylinder
STROKE 2 STROKE 3
Compression of pure air in heating chamber
Release of combustion gases in the cylinder
STROKE 4 STROKE 5Release of pure air into cylinder
Recompression of pure air in the combustion chamber
STROKE 6Exhaust of combustion gases
SECOND APPROACH SIX STROKE
ENGINE
BEARE HEAD ENGINEThis design was developed by Malcolm Beare of Australia. The technology combines a four stroke engine bottom end with an opposed piston in the cylinder head working at half the cyclical rate of the bottom piston. Functionally, the second piston replaces the valve mechanism of a conventional engine. Claimed benefits include a 9% increase in power, and improved thermodynamic efficiency through an increased compression ratio and expansion ratio similar to the miller or atkins cycle
PISTON CHARGER ENGINEIn this engine, similar in design to the Beare head, a "piston charger" replaces the valve system. 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.[12] In the main cylinder, combustion takes place every turn as in a two-stroke engine and lubrication as in a four-stroke. 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 fewer 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 areAspirationPre-compressionGas transferCompressionIgnition andEjection.
ADVANTAGESReduction in fuel consumption by at least 40%
Two expansions(work/Power stroke) in six strokes
Dramatic reduction in pollution ( up to 65%)
Higher overall efficiency
Lower engine temperature & noise level
Due to more air intake, the cooling system is improved
Better scavenging and more extraction of work per
cycle
Less inertia due to lightness of moving parts
DISADVANTAGES
Brake power & indicated power per cycle per cylinder is comparatively lesser
Engine size increases due to many number of cylinders & additional components
Higher manufacturing cost of six stroke engine
APPLICATIONS
Automobiles, heavy goods, construction-site and farm vehicles. motor-pumps, generator sets, stationary engines, etc....intended for agriculture and industry Motorboats