1. BIRLA INSTITUTE OFBIRLA INSTITUTE OF
TECHNOLOGYTECHNOLOGY
((PATNA CAMPUS)PATNA CAMPUS)
DEPARTEMENT OF MECHANCALDEPARTEMENT OF MECHANCAL
ENGINEERINGENGINEERING
PRESENTED BY:-
SHIVAM KUMAR (BE/15250/13)
PRAVEEN KUMAR
(BE/15251/13)
ABINASH PANDA
(BE/5271/13)
2. Introduction :Introduction :
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• Heat engine : It can be defined as any engine
that converts thermal energy to mechanical work
output. Examples of heat engines include: steam
engine, diesel engine, and gasoline (petrol)
engine.
• On the basis of how thermal energy is being
delivered to working fluid of the heat engine,
heat engine can be classified as an internal
combustion engine and external combustion
engine.
3. Types of EngineTypes of Engine
Internal Engine
Petrol Engine Diesel
Engine
External Engine
Steam Engine
Turbines
4. External CombustionExternal Combustion
EngineEngine• In an External
combustion engine,
combustion takes
place inside the
cylinder.
• -Steam engine is an
example of external
combustion engine,
where the working
fluid is steam.
5. IC EnginesIC Engines
• In an Internal
combustion engine,
combustion takes place
within the cylinder.
• Petrol engine is an
example of internal
combustion engine,
where the working fluid
is a mixture of air and
fuel .
6. Internal combustion engines may be classified as :Internal combustion engines may be classified as :
– Spark Ignition engines.Spark Ignition engines.
– Compression Ignition engines.Compression Ignition engines.
• Spark ignition engine (SI engine):Spark ignition engine (SI engine): An engine in whichAn engine in which
the combustion process in each cycle is started by usethe combustion process in each cycle is started by use
of an external spark.of an external spark.
• Compression ignition engine (CI engine):Compression ignition engine (CI engine): An engine inAn engine in
which the combustion process starts when the air-fuelwhich the combustion process starts when the air-fuel
mixture self ignites due to high temperature in themixture self ignites due to high temperature in the
combustion chamber caused by high compression.combustion chamber caused by high compression.
– Spark ignition and Compression Ignition engineSpark ignition and Compression Ignition engine
operate on either a four stroke cycle or a twooperate on either a four stroke cycle or a two
stroke cycle.stroke cycle.
7. • Four stroke cycleFour stroke cycle : It has four piston strokes: It has four piston strokes
over two revolutions for each cycle.over two revolutions for each cycle.
• Two stroke cycleTwo stroke cycle : It has two piston strokes: It has two piston strokes
over one revolution for each cycle.over one revolution for each cycle.
SI Engine & CI Engine have two
types:-
9. Internal combustion EngineInternal combustion Engine
ComponentsComponents:-:-
1. Block : Body of
the engine
containing
cylinders, made of
cast iron or
aluminium.
11. 3. Head3. Head :: The pieceThe piece
which closes the endwhich closes the end
of the cylinders,of the cylinders,
usually containingusually containing
part of the clearancepart of the clearance
volume of thevolume of the
combustioncombustion
chamber.chamber.
12. 4. Connecting Rod4. Connecting Rod
In a reciprocating piston engine ,
the connecting rod or conrod connects
the piston to the crank or crankshaft.
13. 5. Piston5. Piston
Piston
The piston of an internal combustion
engine is acted upon by the pressure of
the expanding combustion gases in
the combustion chamber space at the top
of the cylinder.
14. 6. Piston rings6. Piston rings
A piston ring is a metal rings that fit into
circumferential grooves around the piston and
form a sliding surface against the cylinder
walls.
15. 7. Crankshaftt::
Rotating shaftRotating shaft
through whichthrough which
engine workengine work
output isoutput is
supplied tosupplied to
externalexternal
systemssystems..
16. 8. Camshaft8. Camshaft ::
Rotating shaft usedRotating shaft used
to push open valvesto push open valves
at the proper time inat the proper time in
the engine cycle,the engine cycle,
either directly oreither directly or
through mechanicalthrough mechanical
or hydraulic linkageor hydraulic linkage
(push rods, rocker(push rods, rocker
arms, tappets) .arms, tappets) .
17. 9. Intake manifold9. Intake manifold::
Piping system whichPiping system which
deliver incoming air todeliver incoming air to
the cylinders, usuallythe cylinders, usually
made of cast metal,made of cast metal,
plastic, or compositeplastic, or composite
material . In most SImaterial . In most SI
engines, fuel is addedengines, fuel is added
to the air in the intaketo the air in the intake
manifold system eithermanifold system either
by fuel injectors orby fuel injectors or
with a carburetor.with a carburetor.
18. 10. Exhaust10. Exhaust
manifoldmanifold :: PipingPiping
system whichsystem which
carries exhaustcarries exhaust
gases away fromgases away from
the enginethe engine
cylinders, usuallycylinders, usually
made of cast ironmade of cast iron
19. 11. Spark plug11. Spark plug ::
Electrical deviceElectrical device
used to initiateused to initiate
combustion in ancombustion in an
SI engine bySI engine by
creating highcreating high
voltage dischargevoltage discharge
across anacross an
electrode gapelectrode gap
20. 12. Flywheel12. Flywheel ::
Rotating massRotating mass
with a largewith a large
moment of inertiamoment of inertia
connected to theconnected to the
crank shaft of thecrank shaft of the
engine.engine.
The purpose ofThe purpose of
the flywheel is tothe flywheel is to
store energystore energy ..
21. 13. Fuel13. Fuel
injectorinjector :: AA
pressurizedpressurized
nozzle that spraysnozzle that sprays
fuel into thefuel into the
incoming air (SIincoming air (SI
engines )or intoengines )or into
the cylinder (CIthe cylinder (CI
engines).engines).
22. 14. Combustion chamber14. Combustion chamber:: The endThe end
of the cylinder between the head and theof the cylinder between the head and the
piston face where combustion occurs .piston face where combustion occurs .
The size of combustion chamberThe size of combustion chamber
continuously changes from minimumcontinuously changes from minimum
volume when the piston is at TDC to avolume when the piston is at TDC to a
maximum volume when the piston atmaximum volume when the piston at
23.
24. Four Stock SI Engine & CIFour Stock SI Engine & CI
EngineEngine :-:-
1. SI Engine:- It this engine, cycle of operation is
completed in four stocks of the piston or two strokes
of crankshaft . Each stroke consists of 180 degree of
crankshaft rotation.
Four strokes are follows:-
A) Suction stroke.
B) Compression stroke.
C) Expansion stroke.
D) Exhaust stroke.
25. 1. Suction stroke:-1. Suction stroke:- In suction stroke fuel-In suction stroke fuel-
air mixture enters in the cylindair mixture enters in the cylinderer
26. 2. Compression Stroke:-2. Compression Stroke:-
compression ratio of petrol engine is 6-10compression ratio of petrol engine is 6-10
27. 3. Power or Expansion3. Power or Expansion
strokestroke:-:-
30. 2. CI Engine:-2. CI Engine:-
The diesel engine was first patented in 1892 by Rudolph
Diesel. Like SI Engine, CI Engine complete cycle in 4 stroke.
Four stokes are:-
1. intake or suction stroke:-The intake valve
opens, and fresh air (containing no fuel), is drawn into the
cylinder.
31. 2. Compression stroke:-2. Compression stroke:-
•Both valves stay
closed
•Piston moves from BDC to TDC,
compressing air to 22:1
increases the
temperature inside the
cylinder to above 1000
•Compressing the air to
this extent
32. 3. Power stroke:-3. Power stroke:-
•When the piston is at the end of
compression stroke(TDC) the injector
sprays a mist of diesel fuel into the
cylinder.
•Both valves stay closed
•When hot air mixes with
diesel fuel an explosion takes
place in the cylinder.
•Expanding gases push the piston
from TDC to BDC
33. 4. Exhaust Stroke4. Exhaust Stroke
•Piston moves from BDC to
TDC
•Exhaust valve opens and the
exhaust gases escape
•Intake valve remains
closed
34. 2- Stroke Engine2- Stroke Engine
As the name itself implies,
all the processes in the two
stroke cycle engine are
completed in two strokes.
In the two stroke engine
there is a two opening called
ports are provided in place of
valve of four stroke engines.
One port known as a inlet
port and another port is
known as a exhaust port.
35. Working of the two strokeWorking of the two stroke
petrol enginepetrol engine
•At the beginning of the first stroke piston
Is at the TDC. Piston moves from TDC to
BDC
First stroke:-
•Another A/F/O mixture is sucked into
crankcase while First one is compressed in
cylinder
Intake/ compression StrokeIntake/ compression Stroke
36. Fig. B
Piston uncovers transfer port
During first stroke
Fig. A
Beginning of the first stroke
37. Second strokeSecond stroke :-:- Power/ExhaustPower/Exhaust
StrokeStroke
•In this stroke piston moves from BDC to
TDC.
•Exhaust port is uncovered and
exhaust starts leaving.
39. •Because it is light, can be used at anyBecause it is light, can be used at any
angle, operates at high RPM Weed eatersangle, operates at high RPM Weed eaters
Chain sawsChain saws
BoatsBoats
SnowmobilesSnowmobiles
Dirt bikesDirt bikes
Good uses of two strokeGood uses of two stroke
enginesengines
40. 11/2001 40
Usually don’t use 2 strokesUsually don’t use 2 strokes
in :-in :-
Because of pollution, efficiency, lack of low
RPM power, and convenience of not mixing
oil
– Cars
– Trucks
– Road bikes
– Lawn mowers
– Generators
41. Difference between 4Difference between 4
stroke & 2 strokestroke & 2 stroke
Principle 4 stroke 2 stroke
1.Stroke per cycle
2.Crank rotation per cycle
3.Power stroke per cycle
4.Power
5.Fly wheel
6.Sizeof engine
7.Admission of charge
8.Valves
9.Crankcase
10.Direction of rotation the
crankshaft
11.Lubricant oil consumption
12.Thermal efficiency
13.Mechanical efficiency
14.uses
Four piston stroke
Two crank rotation
Half of speed of crankshaft
In every alternate revolution
Heavy flywheel
Heavier , larger and more
space
Directly into cylinder
Inlet and exhaust valves
It is not hermetically sealed
In one direction
Less
Higher
Low
Cars, tractors, buses
Only two piston stroke
Only one crank rotation
Equal to speed of crankshaft
In every revolution
Lighter flywheel
Lighter , more compact and less space
First admitted into crankcase, then
transfer to engine
In place of valves, ports are there
Hermetically sealed
In both directions
More
Less
High
Mopeds, scooter, motor, cycle
44. Wartsila-Sulzer RTA96-C is the largest IC
engine, but the Space Shuttle Solid Rocket
Boosters are the most powerful (≈ 42
million horsepower (32 hp/lb); not shaft
power but kinetic energy of exhaust stream)
Most powerful shaft-power engine: Siemens
SGT5-8000H stationary gas turbine (340
MW = 456,000 HP) (0.52 hp/lb) used for
electrical power generation
Most powerful internalMost powerful internal
combustion enginecombustion engine
