IC Engines

Course on

Internal Combustion Engine (ICE)

for

Mechanical Engineering

Semester - VI

Term Work Evaluation

Term Work:

• Term work shall consist of minimum 08 experiments,

assignments and written test.

• The distribution of marks for term work shall be as

follows:

Laboratory work (experiments/assignments): ...... (15)

Marks.

Test (at least one): ............... (10) Marks.

Practical Examination:................. (25) Marks.

• TOTAL: ..................... (50) Marks.

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Experiments and Assignments

List of Experiments:

1) Study of carburetor.

2) Study of ignition system.

3) Study of fuel injection system.

4) Morse Test on petrol engine.

5) Speed Test on petrol or/and diesel engine.

6) Load Test on diesel engine (engines).

7) Heat Balance test on diesel or petrol engines.

8) Experimental determination of Air fuel ratio.

9) Exhaust Gas/Smoke analysis of S.I./ C.I. engines

10) Effect of Supercharging on Performance Characteristics of an engine

Practical Examination:

• Practical examination of 2 hours duration based on the laboratory experiments.

• Viva-.voce can be conducted during practical examination. 1/29/2014 Prof. Irfan Shaikh 3

Text and References

Text Books:

1. Internal Combustion Engine - Mathur and Sharma

2. Internal Combustion Engine - E.F. Oberi.

3. Internal Combustion Engine - Domkundwar

4. Internal Combustion Engine - V. Ganesan - TataMcGraw Hill

References:

1.Internal Combustion Engines - Richard Stone - Palgrave Publication

2. Internal Combustion Engine - S.L. Beohar

3. Internal Combustion Engine - Gills and Smith.

4. Internal Combustion Engine - P.M Heldt.

5. Power Plant Engineering - Morse

6. Internal Combustion Engines - V.L. Maleeve

7. Internal Combustion Engines - Taylor.

8. Internal Combustion Engines Fundamentals - John B. Heywood

9. Internal Combustion Engines S.S.Thipse,JAICO.

10. Internal Combustion Engines Willard w.pulkrabek, Pearson Education.

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Course Content

• Construction features and types of IC Engines

• Two stroke and Four stroke engines

• Actual and Ideal cycle analysis

• Carburetion theory and analysis

• Ignition and Injection system analysis

• Combustion phenomena of S.I and C.I Engines

• Fuel injection system for S.I and C.I Engines

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Module - 1

Module - 1

• Construction features of Reciprocating IC Engines

• Types of Combustion Engines

• Two stroke and Four stroke engines

• Comparative study of 2S and 4S Engines

• Ideal cycle analysis viz. Otto, Diesel, Dual cycle

analysis

• Fuel-Air cycle analysis and its effects on

performance parameter

• I.C Engine performance parameters

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Diagram of energy conversion in an

internal combustion engine or gas

turbine

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A typical cut view of IC Engine

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Classification of IC Engine

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Classification based on Cylinder

arrangement

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Applications of Engines

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Cross-section of four-stroke cycle S1 engine showing engine components;

(A) block, (B) camshaft, (C) combustion chamber, (D) connecting rod, (E)

crankcase, (F) crankshaft, (G) cylinder, (H) exhaust manifold, (I) head, (J) intake

manifold, (K) oil pan, (L) piston, (M) piston rings, (N) push rod, (0) spark plug, (P)

valve, (Q) water jacket.

Components of I.C Engine

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Components of I.C Engine

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Cylinder Block with Valve train

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FOUR STROKE ENGINE

OPERATION

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FOUR STROKE ENGINE

OPERATION

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Compression ratio

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Working of 2-Stroke Engine

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Comparative study of 4-S and 2-S

I.C Engine• Cycle completes in 4-S

• Turning moment is not uniform

• One power stroke in every two revolution

• Power to weight density is less

• Lower rate of wear and tear

• Less cooling is required

• Valve arrangement for charge flow

• Initial cost is more

• Volumetric efficiency is more

• Thermal efficiency is higher

• Used where efficiency is important viz., cars, buses, truck etc.

• Cycle completes in 2-S

• Turning moment is uniform

• One power stroke in each revolution

• Power to weight density is more

• Higher rate of wear and tear

• More cooling is required

• Valveless (Ports) arrangement for charge flow

• Initial cost is less

• Volumetric efficiency is less

• Thermal efficiency is lower

• Used where low cost, compactness and light weight are important viz., mopeds, scooters, motorcycles etc.

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Piston cylinder crankshaft

arrangement on I.C Engine

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Piston components of I.C Engine

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Piston and Connecting Rod

Assembly of I.C Engine

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Cutaway of an engine showing the

cylinder, piston, connecting rod, and

crankshaft.

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Actual Indicator diagram on I.C

Engine

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Brake Power and Engine Torque

Characteristics of I.C Engine

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Properties or Characteristics of

Thermodynamics

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Ideal Cycle Analysis (Otto Cycle)

p-v Diagram

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Thermal efficiency vs. Compression ratio

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Ideal Diesel Cycle Analysis

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The dual combustion cycle

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Comparison of Otto, Dual, Diesel cycle

based on performance parameter

( TIt)OTTO > (TIt )DUAL > (TIt )DIESEL

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Comparison contd..

( TIt )DIESEL > (TIt )DUAL > (TIt )OTTO

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Fuel-Air Cycles

• The simple ideal air standard cycles

overestimate the engine efficiency by a

factor of about 2.

• A significant simplification in the air

standard cycles is the assumption of

constant specific heat capacities.

• Heat capacities of gases are strongly

temperature-dependent,

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Variation of efficiency with equivalence ratio

for a constant-volume fuel-air cycle with 1 -

octane fuel for different compression ratios

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Variation of efficiency with compression ratio for a constant-volume

fuel-air cycle with 1 -octene fuel for different equivalence ratios

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Actual Engine or Fuel-Air Cycles• Real engines operate on an open cycle with changing composition.

• There is a loss of mass during the cycle due to crevice flow and blowby past

the pistons.

• In a real engine inlet flow may be all air, or it may be air mixed with up to 7%

fuel.

• Specific heats of a gas have a fairly strong dependency on temperature and

can vary as much as 30% in the temperature range of an engine (for air, cp =

1.004 kJ/kg-K at 300 K and cp = 1.292 kJ/kg-K at 3000 K ).

• Heat loss during combustion lowers actual peak temperature and pressure

from what is predicted. The actual power stroke, therefore, starts at a lower

pressure, and work output during expansion is decreased.

• SI engines will generally have a combustion efficiency of about 95%, while CI

engines are generally about 98% efficient.

• SI engine is always somewhat less than what air-standard Otto cycle analysis

predicts. This is caused by the heat losses,. friction, ignition timing, valve

timing, finite time of combustion and blowdown, and deviation from ideal gas

behavior of the real engine.1/29/2014 Prof. Irfan Shaikh 42