JOURNAL OF MECHANICAL ENGINEERING AND
TECHNOLOGY
Journal of Mechanical Engineering
and Technology (JMET)
(JMET)ISSN XXX–XXX (Print),
ISSN XXX – XXX (Online), Volume 1, Issue 1, July -December (2013)
ISSN 2347-3924 (Print)
ISSN 2347-3932 (Online)
©
Volume 1, Issue 1, July-December (2013), pp. 01-15
© IAEME: http://www.iaeme.com/JMET.asp
JMET
IAEME
NEW 5 STROKE ENGINE WITH SPLITTING CONCEPT
Rajkumar Lalwani1, Shaleen Bahadur2
1
(Automobile, SRM University, India)
(Mechanical, SRM University, India)
2
ABSTRACT
This is about 5 stroke engine with splitting concept based on a radical
Thermodynamic cycle. The design deals with 3 cylinders which involve 5 strokes (Intake,
Compression, Power, Added expansion and exhaust). It is a small effort to increase the power
output and thus deliver optimum performance of the engine with least possible pollutants.
The Design involves 3 cylinders called the compression cylinder, Expansion Cylinder and the
Exhaust Cylinder. Fresh Charge is inducted and compressed to a high pressure in 1st cylinder
(intake and compression) from where it is transferred to 2nd cylinder where spark ignition is
given thus leading to the expansion stroke (+ive work).The energy left in the gases after the
expansion stroke is utilized by transferring them to the 3rd cylinder by pushing the piston
down thus giving added expansion stroke and finally expelling the hot exhaust gases with no
energy left to the atmosphere. The major benefits include variable compression & expansion
ratio due to separate cylinders with no risk of knocking. Other benefits include cooler charge
induction, built in supercharging varying compression cylinder size, maximum energy
utilization of exhaust gases, complete fuel combustion and possibility of miller cycle by
separate expansion and compression cylinders.
Keywords – Added expansion, Splitting, Variable Compression ratio
1. INTRODUCTION
It was year 1876 when 4 stroke engine based on Otto cycle was invented and after
nearly 100 years of its existence, the OTTO cycle is going to become obsolete. It’s the time
for something very new engine technology to come based on a radical thermodynamic cycle
and change the way of its working what the entire world has seen. Today in the era of modern
technology the world is struggling towards the invention of an engine that can deliver the
optimum performance in a vehicle be it rotary engine of Mazada RX-7, RX-8. One of the
most important steps in the history is evolution of the 5 stroke internal combustion engine.
Though engine consists of a number of complex parameters but its 4 important factors are
Power, Torque, Efficiency and Work output. Throughout the years there has been an
immense struggle in achieving the maximum values of all these 4 parameters simultaneously
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
but it has not been possible due to their dependency on different factors. A 5 stroke internal
combustion engine, no doubt has a greater amount of work done but at the same time it
blocks the increase of a very important factor compression ratio which can help us in
achieving immense power and efficiency. Since in a 5 stroke internal combustion engine, the
compression and power stroke take place in the same cylinder due to which there is a risk of
knocking because of that we cannot increase the compression ratio beyond a certain extent
and there comes need of separation of compression and power stroke in an engine.
2.
OPERATIONS
This cycle involves the various operations which are described as follows:2.1 Intake
Intake of fresh charge happens in 1st cylinder called compression cylinder, where the A/F
mix or Air alone is inducted into the cylinder through inlet valve opening. And this mix is
later used for next stroke.
2.2 Compression
Charge inducted is compressed in the 1st cylinder by the piston’s upward movement where
the intake valve and the transfer port of the 1st cylinder is kept closed for the entire stroke.
Thus the charge gets compressed to high pressure and ready to get transferred to the 2nd
cylinder called power cylinder for combustion.
2.3 Power
Compressed charge is transferred from the 1st cylinder to the 2nd cylinder through the
transfer port and spark is given for combustion to take place in the second cylinder called
power cylinder. Thus due to the heat released during the combustion, piston is pushed down
to give a first positive work output and piston reaches BDC to complete its power stroke.
2.4 Added Expansion
The burnt charge during the power stroke is then transferred to the 3rd cylinder for further
extraction of work from the left energy of the burnt charge. This burnt charge is allowed to
expand in the 3rd cylinder called expansion chamber for another positive work output
increasing its overall thermal efficiency.
2.5 Exhaust
In this stroke the gases which were left with no energy after expansion in 3rd cylinder are
then sent out through the exhaust valve.
3.
FIGURES AND TABLES
3.1
Engine design Line diagram
Figure 1 represents basic line diagram of 5 stroke engine with splitting concept. It
shows all 3 cylinders, transfer ports, spark plug & piston in place. Piston 1 leads piston 2 by
20 degrees to allow all compressed charge to enter in cylinder 2 and take part in combustion
for max power output.
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Journal of Mechanical Engineering and Technology (JMET)
(JMET), ISSN 2347-3924
3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
Fig.1
3.2 Ricardo Wave Build Model
Fig.2
3.3 Input Data and Design Specifications
Table No. 1
No. of Cylinders
3
Bore
87mm
Stroke
96mm
Head Volume
50 cc
Spark Plug Volume
0.8cc
Piston Dish
0.2 cc
Squished Gasket Thickness 2mm
Piston Pin Height
31.4mm
Rod Length
150mm
Block Deck
227.45mm
Piston Deck
2.95mm
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.4 Output Results
Table No.2
Deck Volume
Total Combustion chamber volume
Cylinder Displacement
Engine Displacement
Squished Gasket Volume
-20.47cc
44.41cc
680.10cc
2040.29cc
13.88 cc
3.5 Air and Fuel flow Calculations
3.5.1 Input Data
Table No.3
Engine Testing rpm
Air Fuel mass ratio
Volumetric Efficiency
Estimated Brake Specific Fuel Consumption
Air Density
6000 rpm
14.7:1
98%
0.45bhp/lbs/hr
0.075lbs/cu-ft
3.5.2 Output Data
Table No.4
Volumetric Air Flow (STP)
211.83 cfm
Mass Airflow
953.25lbs/hr
Required mass fuel flow
64.85 lbs/hr
Estimated hp based on BSFC
144.10 bhp.
BSAC
6.62hp/lbs/hr.
Mass airflow per minute
15.89lbs/min.
Torque at 6000 rpm
126.1ft/lbs.
Mean Piston Speed
19.6 m/s.
3.6 Gas Flow Calculations
3.6.1Input Data
Table No.5
Valve Diameter
1.496 inches
Valve Lift
0.35 inches
3.6.2 Output Data
Table No.6
Engine rpm
Mean Gas Velocity through valve
6000 rpm
364.90mph
3.7 Turbocharger Calculations
3.7.1Input parameters
Table No.7
Engine Speed
6000 rpm
Boost
14 psi
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.7.2 Output Results
Table No.8
Minimum Estimated Horse Power
Maximum Estimated Horse Power
200.44hp
272.02hp
3.8 Valve Lift Iterations & Profile
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Table No.9
Angle
0.0
10.0
20.0
30.0
40.0
70.0
110.0
120.0
130.0
138.0
146.0
156.0
166.0
206.0
228.0
244.0
264.0
280.0
Lift
0.00
0.02
0.17
0.62
1.42
4.87
8.19
8.60
8.83
8.89
8.83
8.60
8.19
4.87
2.28
0.78
0.10
0.00
Fig.3
It can be seen from Fig.3 that as the piston moves from BDC to TDC the valve goes
on closing facilitating proper compression and at TDC it goes off completely and again after
expansion stroke the valve starts opening thus paving the way for the removal of burnt and
exhaust gases.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.9 Velocity per degree Crank angle
Fig.4
It is evident from the Fig.4 that at the time of expansion or power stroke due to the
production of maximum power the velocity is maximum.
3.10 Acceleration per degree Crank angle
Fig.5
3.11 Specific Heat Vs Temperature
Fig.6
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
Fig.6 shows, As the temperature increases the specific heat increases i.e. more energy is
required to increase the temperature by 1 K and due to this an optimum temperature is
maintained at constant fuel supply and thus preventing the engine from reaching absolutely
high temperature in turn reducing knocking.
3.12 Piston Velocity per Degree Crank angle
Fig.7
3.13 Piston Velocity Vs Crank Angle
Fig.8
Fig.8 shows that at the beginning of the exhaust stroke the piston velocity peaks
which indicates better scavenging process and better induction of fresh charge during the next
cycle. Also at the beginning of expansion stroke the velocity peaks giving higher speeds.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.14 Piston Heat Transfer Rate
Fig.9
Fig.9 shows that as the time increases the heat transfer rate decreases thus maintaining
the optimum temperature and preventing the damage caused due to high temperatures
phenomenon such as knocking. It also eliminates the need for a complex cooling system.
3.15 Exhaust Mass Flow Rate
Fig.10
Fig.10 shows that the exhaust mass flow rate is maximum at the exhaust stroke and for some
duration during the expansion which facilitates proper combustion of fuel.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.16 Fuel Burn Rate
Fig.11
Fig.11 shows that the fuel burn rate is highest at the expansion stroke which is the
need for complete combustion .It can be seen that during the compression stroke the fuel burn
rate is negligible which prevents the rising of pressure and temperature thus reducing the risk
of knocking. It also indicates a better fuel economy.
3.17 Heat Release Rate
Fig.12
Fig.12 shows that the heat release rate is highest during the compression stroke which is due
to high compression ratio and which facilitates better combustion.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.18 Heat Transfer Rate
Fig.13
Fig.13 shows that the heat transfer rate is highest during the expansion stroke and
minimum during the exhaust stroke this prevents the damage of exhaust valves. Since the
heat transfer rate is highest during the expansion stroke it leads to the complete combustion
of fuel.
3.19 Inner Wall Temperature
Fig.14
Fig.14 shows that the inner wall temperature is highest during the expansion stroke
due to the complete combustion of fuel and production of maximum power and as the piston
moves down from TDC to BDC the temperature falls down and thus a constant temperature
is maintained for the idler strokes to prevent knocking.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.20 Engine torque Vs Crank Angle
Fig.15
Fig.15 shows that the engine torque is maximum during the expansion stroke. It
produces a torque of 10 Nm for the functioning of idler strokes.
Another feature of this graph is that the torque goes on increasing during the
compression stroke which helps in achieving higher compression ratio and thus greater
power. As the expansion stroke begins the torque goes down due to the fall of pressure.
3.21 Intake Mass Flow Vs Crank Angle
Fig.16
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Journal of Mechanical Engineering and Technology (JMET),
(JMET) ISSN 2347-3924
3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
3.22 Indicated Torque vs crank angle
Fig.17
Fig.17 shows that the production of torque is highest at the expansion stroke thus
giving maximum acceleration to the vehicle and also greater power.
4. EXPERIMENTAL METHODO
METHODOLOGY
Work done is what decides the efficiency of any engine and it is given by the
following formula:-
In the proposed design two expansion strokes occur i.e. two +ive work outputs.
Whereas conventional 4 stroke engine design has only one expansion stroke i.e. only one
positive work output.
P-V
V Curve of this engine design obtained from Ricardo wave is compared with the
P-V
V curve of conventional 800 cc 4 stroke engine and the Areas of both curves are measured.
Areas are as follows:5 Stroke Split Engine design- 60.205 cm2
Conventional 4 stroke design- 44.75 cm2
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
Fig.18
Fig.19 (5 stroke engine design)
Fig.20 (4 stroke engine design)
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
Since area of 5 stroke engine design is larger (60.205cm2) than the conventional 4 stroke
design (44.75cm2), which results in more work output and power. This validates this design.
The above results are simulated in Ricardo Wave Engine simulation Software and
Spreadsheet too. Some of the parameters are assumed like conventional 4- Stroke engine and
based upon that the results were obtained for different operating conditions of this new
engine design.
Results obtained are totally different as the cycle, which engine operates on is entirely
different than that of the conventional.
5.ADVANTAGES
a. Variable Compression ratio because of separate compression cylinder from combustion
chamber.
b.High C.R. possible with no risk of knocking.
c. Variable Expansion ratio because of separate expansion cylinder from compression
cylinder.
d.Cool charge induction because of the transfer port which reduces the knocking tendency.
e. Built in supercharging as the compression cylinder size can be varied independent to bore
size.
f. Miller cycle is possible as expansion cylinder is independent to compression cylinder.
g.Maximum energy utilization of exhaust gases.
h.No gear reduction mechanism b/w the camshaft & crankshaft to transmit motion for valve
opening, reducing complexity.
6. CONCLUSION
The technology provides a simple but elegant solution to the problem of how to meet
modern demands for increased engine efficiency, improved power, downsizing and lower
emissions. Since Better performance is always a call of the day, the design aims to increase
the fuel economy and reduce emissions to save the planet.
ABBREVIATIONS
1. cfm – cubic feet per minute
2. lbs/hr – pounds/hour
3. bhp – brake horse power.
4. lbs/cu-ft-pounds/cubic feet
5. hp/lbs/hr – horse power/pounds/hour.
6. Rpm – revolutions per minute
7. m/s-metre/second
8. mm- millimetre
9. cm- centimetre
10. cc- cubic centimeter.
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Journal of Mechanical Engineering and Technology (JMET), ISSN 2347-3924 (Print),
ISSN 2347-3932 (Online), Volume 1, Issue 1, July -December (2013)
REFERENCES
BOOKS:
[1]
Auto Design by Prof. R. B. Gupta, Satya prakashan, ISBN 81-7684-010-6
[2]
Internal Combustion Engine Fundamentals by John B. Heywood.
Advances in Vehicle Design by John Fenton, ISBN 1 86058 181 1
[3]
[4]
Internal Combustion engines by V. Ganesan.
Design and Simulation of Two-Stroke Engines by Gordon P. Blair,Published by
[5]
Society of Automotive Engineers,Inc. ,ISBN 1-56091-685-0.
JOURNAL PAPERS:
[1]
Five Stroke Internal Combustion Engine A new concept for internal combustion
engines by Gerhard Schmitz, St.Vith 2011, Belgium
[2]
A Six-Stroke, High-Efficiency Quasiturbine Concept Engine With Distinct,
Thermally-Insulated Compression and Expansion Components by George Marchetti
and Gilles Saint-Hilaire www.quasiturbine.com/QTMarchettiSthSixStroke0509.pdf
[3]
Full-Time Gasoline Direct-Injection Compression Ignition (GDCI) for High and Low
NOx and PM
[4]
Design Details of the BMW-801A Engine by Myles V. Cave, an article published in
November and December,1942,(Volume 41,Numbers 11 and 12) issues of Aviation
Magzine published by Mcgraw-Hill Publishing Company of Newyork,NY,USA.
WEBSITES:
http://www.popsci.com/cars/article/2011-01/split-cycle-engine-design-could-improve[1]
fuel-economies-50-percent
[2]
http://www.5-stroke-engine.com.
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