Six stroke IC engine
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Transcript of Six stroke IC engine
Welcome To
Project seminar On
SIX STROKE IC ENGINE
Prepared by : Trambadiya vaibhav r.(1216BEME30059)
: Vachhani yagnik k. (1216BEME 30061)
Abstract
Modern world thrives on heat energy used in different forms.
Automobile industries is ever-growing industry.
95% of the automobile run on IC engines which are powered by fossil fuels.
Aim of thermal is to convert the heat energy to mechanical energy.
Efficiency of automobile is 30%
In a six stroke engine there are six strokes and out of these there are two power strokes.
The automotive industry may soon be revolutionized by a new six stroke design which adds a second power stroke, resulting in much more efficiency with less amount of pollution.
Introduction
The term six stroke engine describes two different approaches in the
internal combustion engine, developed since the 1990s, to improve its
efficiency and reduce emissions.
A six stroke engine derived its name from the fact that it is a mixture of two
and four stroke engine.
Two technical modifications in 4-stroke to 6-stroke.
Six stroke engines captures the wasted heat from the 4-stroke Otto cycle ,
creates steam and cools engine by providing free power stroke.
Working principal
A six stroke engine describes a number of different approaches in the
internal combustion engine to capture the waste heat from the four stroke
Otto cycle and use it to power an additional power and exhaust stroke of the
piston.
Designs either use steam or air as the working fluid for the additional
power stroke.
As well as extracting power, the additional stroke cools the engine and
removes the need for a cooling system making the engine lighter and giving
40% increased efficiency over the Otto Cycle.
1st stroke (suction stroke) : During the first stroke the inlet valve opens and
air-fuel mixture from carburetor is sucked into the cylinder through the inlet
valve and piston moves from TDC to BDC.
2nd stroke (compression stroke) : During the second stroke, piston moves
from BDC to TDC, both the inlet valve and exhaust valve are closed and the
air-fuel mixture is compressed.
3rd stroke (1st power stroke) : During the third stroke, power is obtained from
the engine by igniting the compressed air- fuel mixture using a spark plug. Both
valves remain closed. Piston moves from TDC to BDC.
4th stroke (exhaust stroke) : During the fourth stroke, the exhaust valve opens
to remove the burned gases from the engine cylinder. Piston moves from BDC
to TDC
5th stroke (2nd power stroke) : During the fifth stroke, the exhaust valve
remains close and the air inlet valve open. Fresh air from the air inlet valve
enters the cylinder through the secondary air induction system. Piston moves
from TDC to BDC. In a six-stroke engine, when the combustion chamber
temperature reaches approx. 400 °F (200 °C). Just before the fifth stroke,
fresh water is injected directly into the hot combustion chamber through the
engine's fuel injector pump, which is quickly turned to superheated steam,
which causes the water to expand to 1600 times its volume and forces the
piston down for an additional Power stroke.
6th stroke (2nd exhaust stroke) : During the sixth stroke, the air exhaust
valve remains open. The air sucked into the cylinder during the fifth stroke is
removed to the atmosphere through the air exhaust valve. Piston moves from
BDC to TDC and six stroke cycle is completed.
Application
The industry trend away from cheaper two-stroke power in favor of
costlier but cleaner four-stroke engines in both Europe, Japan and South
East Asia makes a concept like the Beare six-stroke, which offers the best
of both worlds, project a strong case towards volume manufacture.
150cc six-stroke Taiwanese single-cylinder bike from Yingang is ready to
roll.
Types of six stroke ic engine
A. Single piston designs
A.1 Griffin six-stroke engine
A.2 Bajulaz six-stroke engine
A.3 Velozeta six-stroke engine
A.4 NIYKADO Six Stroke Engine
A.5 Crower six-stroke engine
B. Opposed piston designs
B.1 Beare Head
B.2 M4+2
B.3 Piston charger engine
Modified part
To make six-stroke engine from conventional four-stroke engine, a few
modifications must be done to specific parts on the conventional engine to
be sure that the new engine with six-stroke will run successfully.
A Mitsubishi single cylinder spark ignition engine was used to apply these
modifications on it.
These modifications are :1.Crankshaft to Camshaft Ratio Modification
2.Cam lobes
3.Valve timing diagram
Crankshaft to Camshaft Ratio Modification
In the six stroke engine the crankshaft has 1080 degrees of rotation for 360
degree rotation of the camshaft per cycle.Hence their corresponding sprockets
are having teeth in the ratio 3:1.
In the original four stroke engine the teeth of the sprockets of the crankshaft
and the Camshaft was in 2:1 ratio.
The 34 teeth sprocket of the four stroke engine camshaft was replaced by a 42
teeth sprocket in the six stroke engine.The camshaft sprockets were also
replaced from 17 teeth to 14 teeth to convert the four stroke engine into six
stroke engine.
Cam lobes
In the six stroke engine the 360 degrees of the cam has been divided into 60
degrees among the six strokes.
The valve provided at the exhaust has to be kept open during the fourth, fifth
and the sixth stroke.The cam has been made double lobed in order to avoid the
hitting of the exhaust valve with the piston head.
The profiles of the exhaust and the inlet cams have been shown in the figure
Valve timing diagram
The valve timing of the four stroke Honda engine has been changed.
The inlet valve opening (IVO) is 0° at TDC, same as that of the four
stroke Honda activa engine.
Inlet valve closes (IVC) at 25° after BDC, same as that of the four stroke
engine. Exhaust valve opens (EVO) 0° at BDC, which in the original
engine was 25° before BDC.
Velozeta reduced this 25° advanced opening of exhaust valve to extract
maximum work per cycle.
Exhaust valve closes 10 degree before TDC in order to prevent the loss of
air fuel mixture through the exhaust valve.
Advantages
The weight and power loss of conventional cooling system parts can be eliminated.
There is 40% reduction in fuel consumption.
Extracts work from heat that is ordinarily lost through the cooling system of a conventional engine.
Reduces exhaust emissions per a given power range.
Steam stroke cools the engine internally hence the use of much higher compression ratios.
Dramatic reduction in pollution normally up to 65%.
Lower engine temperature so easy to maintain the optimum engine temp. level for better performance.
Higher overall efficiency
Limitations and Obstacles
Injecting relatively cold water into a hot metal piston can damage it over
time from thermal expansion and contraction.
Separate water tank would have significant weight and space penalties
A steam-free cool down reduces the temperature inside the combustion
chamber.
Cold climate anti-freezing measures would be needed in the water
reservoir.
betterment
To prevent damages due to the action of cold water, we can utilize the
exhaust gases for pre- heating of water.
We can use a condenser instead of a separate water tank which will reuse
the distilled water for a period of cycles.
To compensate the temperature drop inside the chamber we can further
increase the Compression ratio which increases the power output making it
suitable for higher power requirements.
Conclusions
The concept of Six Stroke Engine seems to be rather eco-friendly andlow fuel consuming which can fulfill the needs of near future.
A lot of experiments are being conducted in order to improve theefficiency and workability of the engine.
In a six stroke engine the energy absorption is less because of slower acceleration of reciprocating parts The piston speed of the upper piston is about a quarter of the main piston; therefore its service life should be at least twice that of the main piston.
In the Beare design, per single cylinder, the number of parts is 15 compared to a four stroke of approx 40 to 50 parts. Also, to reduce manufacturing costs the head and block can be machined in one piece.
Better fuel economy and cleaner burning longer service intervals and considerably reduced tooling costs when compared with a conventional four-stroke design.
references
http://www.researchpublish.com
http://www.wikipedia.org/wiki/six_stroke_engine/
International Journal of Engineering Research & Technology
http://www.seminarsonly.com
http://www.google/sixstroke ic engine/