IC engine full chapter ppt IC engine full chapter pdf Engineering student notes Engineering notes IC engine notes IC engine full chapter Petrol engine Diesel engine IC engine fuel engineering pdf Thermodynamics book pdf Thermal engineering 1 pdf Thermal engineering 2 pdf Internal combustion engine External combustion engine Spark ignition Compression ignition

1. Prepared By:-
Mr. A M Ambaliya
Dr. S. & S. S. Ghandhy College of Engineering &
Technology, Surat.
Thermal Engineering-II (4351903)
5th Semester Diploma Mechanical Engineering
1

2.  A heat engine is a device that converts
thermal energy (heat) into mechanical
work, or vice versa, by utilizing the
principles of thermodynamics.
 It operates in a cyclic manner, where it
absorbs heat from a high-temperature
reservoir, converts a portion of that
heat into mechanical work, and then
releases the remaining heat to a low-
temperature reservoir.
 The most common types of heat
engines are internal combustion
engines and steam engines.
2
 Heat Engine : -

3. 3
Heat Engine
External
Combustion
Engine
Internal
Combustion
Engine

4. 4
Heat Engine
External Combustion
Engine
Internal
Combustion
Engine

5.  An Internal Combustion Engine (ICE) is a type of heat
engine that generates mechanical power by burning fuel
directly within a combustion chamber.
 This combustion produces high-temperature and high-
pressure gases that drive a piston or a turbine, ultimately
converting the energy from the fuel into useful
mechanical work.
 Internal combustion engines are widely used in various
applications, including automobiles, motorcycles, trucks,
airplanes, and certain power generators.
5
 Internal Combustion Engine:-

6. 6
 Basic Nomenclature of I.C. Engine:-

7. 7
Working of 4-Stroke Petrol Engine
1
Suction
Stroke
2
Compression
Stroke
3
Expansion
Stroke
(Power Stroke)
4
Exhaust
Stroke

8. 8

9. 9
Working of 4-Stroke Diesel Engine
1
Suction
Stroke
2
Compression
Stroke
3
Expansion
Stroke
(Power Stroke)
4
Exhaust
Stroke

10. 10
Working of 2-Stroke Petrol Engine
1. Compression and
Combustion Stroke
(Upward Stroke)
2. Exhaust and Intake
Stroke
(Downward Stroke)

11. 11
Working of 2-Stroke Petrol Engine
1. Compression and
Combustion Stroke
(Upward Stroke)
2. Exhaust and Intake
Stroke
(Downward Stroke)

12. 12
Comparison of
2-Stroke 4-Stroke
Cycle: A 2-stroke engine completes its power
cycle in two strokes of the piston
Cycle: A 4-stroke engine completes its power
cycle in four strokes of the piston
Simplicity: Simpler due to fewer moving parts.
They don't have valves and instead rely on
ports in the cylinder wall
Complexity: more complex due to the
additional components such as valves,
camshafts, and an oiling system.
Efficiency: Lower fuel-efficient and produce
higher emissions
Efficiency: More fuel-efficient and produce
lower emissions
Lubrication: Engines require oil to be mixed
with the fuel to provide lubrication for the
engine's moving parts.
Lubrication: Separate oil reservoir and use a
system of pumps and passages to deliver oil to
various engine components.
Power Output: They tend to have higher
power-to-weight ratio. Bcz they produce
power on every revolution of the crankshaft.
Power Output: They tend to have lower
power-to-weight ratio. Bcz they produce
power every 2nd revolution of the crankshaft.
Applications: Boats and Marine Engines,
Aeroplan (radial engine), Lawnmowers, Dirt
Bikes.
Applications: cars, trucks, motorcycles, as well
as in stationary applications like generators

13. 13
Comparison of
S.I. Engine C.I. Engine

14. 14

15. 15

16. 16

17. 17
Classification of I.C. Engine.
1. Based on Ignition:
• Spark Ignition (S.I.) Engines: These engines use a spark
plug to ignite the air-fuel mixture. They are commonly used in
gasoline-powered vehicles.
• Compression Ignition (C.I.) Engines: Also known as diesel
engines, they rely on the high compression of air to ignite the
fuel. They are commonly used in diesel-powered vehicles.
2. Based on Number of Strokes:
• 2-Stroke Engines: Complete a power cycle in two strokes of
the piston - compression and combustion/exhaust.
• 4-Stroke Engines: Complete a power cycle in four strokes of
the piston - intake, compression, combustion, and exhaust.

18. 18
Classification of I.C. Engine.
3. Based on Arrangement of Cylinders:
A. Inline Engine:
B. V-Type Engine:
C. W-Type Engine:
D. Opposite Piston Engine:
E. Opposite Cylinder Engine:
F. Radial Engine:

19. 19
Classification of I.C. Engine.
4. Based on Cooling Method:
• Liquid-Cooled Engines:
Use a coolant (usually a
mixture of water and
antifreeze) circulated
through a radiator to
dissipate heat.
• Air-Cooled Engines: Rely
on the circulation of air
around the engine to
dissipate heat.

20. 20
Classification of I.C. Engine.
5. Based on Thermodynamic Cycle:
• Otto Cycle Engines: S.I engine
• Diesel Cycle Engines: C.I engine.
6. Based on Fuel Type:
• Gasoline Engines: These engines run on gasoline (petrol).
• Diesel Engines: These engines run on diesel fuel.
• Natural Gas Engines: These engines run on natural gas.
• Alternative Fuel Engines: These engines are designed to
run on alternative fuels like ethanol, biodiesel, hydrogen, etc

21. 21
Classification of I.C. Engine.
6. Based on Ignition System:
 Bike, Scooter, Moped
etc.
 Car, Truck, Bus etc.
 ( Crank Start
Engine)

22. 22
Otto Cycle (P-V, T-S Diagram).

23. 23
Otto Cycle (Efficiency).

24. 24
Diesel Cycle (P-V, T-S Diagram).

25. 25
Diesel Cycle (Efficiency).

26. 26
Dual Cycle (P-V, T-S Diagram).

27. 27
Valve Timing Diagram- 4 Stroke S.I. / C.I. Engine
Ideal Valve Timing

28. 28
Valve Timing Diagram- 4 Stroke S.I. Engine

29. 29
Valve Timing Diagram- 4 Stroke C.I. Engine

30. 30
Port Timing Diagram- 2 Stroke S.I. Engine

31. 31
Port Timing Diagram- 2 Stroke C.I. Engine

32. 32
Performance Measurement of I.C. Engine.
1. Indicated Power (IP):
• Indicated Power( IP), is the power that is produced in the
cylinder of an engine as a result of the combustion of fuel.
N= N (2-Stroke engine)
N= N/2 (4-Stroke engine)

33. 33
Performance Measurement of I.C. Engine.
1. Measurement of Indicated Power (IP):
 Morse Test:
• The Morse Test is conducted in a multi-cylinder type of S.I/C.I engines.
• First the brake power generated at a certain load and rpm is calculated by a
dynamo meter (BP).
• Then the combustion in one of the cylinders is stopped , by removing the spark
plug or disconnecting it.
• The brake power is then calculated (BP1)
• The difference in the brake powers measured gives the Indicated Power
developed in the first cylinder. (IP1)
• This is continued for the other cylinders by removing the spark plugs one at a
time, and the IP of each cylinder is calculated.

34. 34
Performance Measurement of I.C. Engine.
1. Measurement of Indicated Power (IP):
 Morse Test:
• BP = (IP1+IP2+IP3+IP4 ) – FP ………………(A) (FP= FP1+FP2……+FPn)
• BP1 = (0+IP2+IP3+IP4 ) – FP ………………(1) Cylinder 1 cut-off
• BP2 = (IP1+0+IP3+IP4 ) – FP ………………(2) Cylinder 2 cut-off
• BP3 = (IP1+IP2+0+IP4 ) – FP ………………(3) Cylinder 3 cut-off
• BP4 = (IP1+IP2+IP3+0 ) – FP ………………(4) Cylinder 4 cut-off
 BP – BP1 = IP1 [ Equ. (A) – (1) ]
 BP – BP2 = IP2 [ Equ. (A) – (2) ]
 BP – BP3 = IP3 [ Equ. (A) – (3) ]
 BP – BP4 = IP4 [ Equ. (A) – (4) ]

35. 35
Performance Measurement of I.C. Engine.
2. Brake Power (BP):
• It is useful power available at the crank shaft or clutch shaft.
• The brake power is less than indicated power because of the
following losses as power flows from the cylinder to the crank shaft.
I. Friction between the cylinder surface and piston rings, in
bearings, gears, valve mechanism etc.
II. Resistance of air to fly wheel rotation
III.Power required to drive auxiliaries – fuel pump, lubrication
pump, radiator circulation pump etc.
• Brake power is measured by device called Dynamometer.

36. 36
Performance Measurement of I.C. Engine.
2. Brake Power (BP): 1. Rope Brake Dynamometer

37. 37
Performance Measurement of I.C. Engine.
2. Brake Power (BP): 1. Rope Brake Dynamometer
Let, W= Dead weight
S = Reading of spring balance
N = Speed of the shaft of the prime mover
D = Diameter of the flywheel or diameter of the rim of the pulley
d = Diameter of the rope
• Force = The net load on the brake = (W – S) (N)
• Torque = Force x dist. = (W – S) x
(D+d)
2
(Nm)
• Brake Power = Torque x Angular speed of Engine (Nm/s)(J/s)(watts)
𝐁. 𝐏. = 𝑾 − 𝑺 ×
(D+d)
2
×
2ߨܰ
60
(watts)

38. 38
Performance Measurement of I.C. Engine.
2. Brake Power (BP): 2. Rope Brake Dynamometer
𝐁. 𝐏.
W × 𝐋 × 2ߨܰ
60
(𝒘𝒂𝒕𝒕𝒔)
L
W

39. 39
Performance Measurement of I.C. Engine.
2. Brake Power (BP): 3. Electrical Dynamometer(Eddy current)
P = V x I, where
P is power in watts,
V is voltage
I is current.
Torque = Force x dist.
BP = Torque x
2ߨܰ
60
(𝑾𝒂𝒕𝒕𝒔)

40. 40
Performance Measurement of I.C. Engine.
2. Brake Power (BP):
4. Hydraulic
Dynamometer
Torque = Force x dist.
BP = Torque x
2ߨܰ
60
(𝑾𝒂𝒕𝒕𝒔)

41. 41
Performance Measurement of I.C. Engine.
3. Friction Power (BP):
• Friction power in an internal combustion engine refers to the
power that is lost due to various forms of friction within the
engine itself.
(piston cylinder wall, cam shaft, crank shaft bearing)
BP = IP - FP
‫؞‬FP = IP - BP
• This power is not
available for useful
work and is typically
converted into heat.

42. 42
Performance Measurement of I.C. Engine.
 Different Efficiency of Engine:
η𝐢𝐭𝐡 =
Indicated Power (IP)
mf ×𝑪.𝑽.
1. Indicated Thermal Efficiency:
2. Brake Thermal Efficiency: η𝐛𝐭𝐡 =
Brake Power (BP)
mf ×𝑪.𝑽.
3. Mechanical Efficiency: η𝒎 =
Brake Power (BP)
Indicated Power (IP).
4. Volumetric Efficiency: η𝒗 =
mass of air (ma)
𝑺𝒘𝒆𝒑𝒕 𝑽𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝑪𝒚𝒍𝒊𝒏𝒅𝒆𝒓

43. 43
Performance Measurement of I.C. Engine.
 Heat Balance Sheet: