A textbook of internal combustion engines : (including air compressors and gas turbines and jet propulsion : S.I. units

1030 Pages·2016·19.548 MB·English

by  R. K. Rajput

INTERNAL COMBUSTION ENGINES
(Including Air Compressors, Gas Turbines and Jet Propulsion)

INTERNAL
COMBUSTION ENGINES
(Including Air Compressors, Gas Turbines
and Jet Propulsion)
[A textbook for the students preparing for B.Tech, B.E., AMIE,
UPSC (Engg. Services) and GATE Examinations]
SI UNITS
By
Er. R.K. RAJPUT
M.E. (Hons.), Gold Medallist, Grad. (Mech. Engg. & Elect. Engg.); M.I.E. (India);
M.S.E.S.I.; M.I.S.T.E.; C.E. (India)
Recipient of:
“Best Teacher (Academic) Award”
“Distinguished Author Award”
“Jawahar Lal Nehru Memorial Gold Medal”
for an outstanding research paper
(Institution of Engineers–India)
Principal (Formerly):
 Thapar Polytechnic College;
 Punjab College of Information Technology,
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A TEXTBOOK OF INTERNAL COMBUSTION ENGINES
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CONTENTS
Chapter Pages
1. BASIC CONCEPTS OF THERMODYNAMICS 1–32
1.1. Definition of Thermodynamics ... 1
1.2. Thermodynamic Systems ... 2
1.2.1. System, boundary and surroundings ... 2
1.2.2. Closed system ... 2
1.2.3. Open system ... 2
1.2.4. Isolated system ... 3
1.2.5. Adiabatic system ... 3
1.2.6. Homogeneous system ... 3
1.2.7. Heterogeneous system ... 3
1.3. Pure Substance ... 3
1.4. Thermodynamic Equilibrium ... 3
1.5. Properties of Systems ... 3
1.6. State ... 4
1.7. Process ... 4
1.8. Cycle ... 4
1.9. Point Function ... 5
1.10. Path Function ... 5
1.11. Temperature ... 5
1.12. Zeroth Law of Thermodynamics ... 6
1.13. Pressure ... 6
1.13.1. Definition of pressure ... 6
1.13.2. Unit of pressure ... 7
1.13.3. Types of pressure measurement devices ... 7
1.14. Reversible and Irreversible Processes ... 8
1.15. Energy, Work and Heat ... 9
1.15.1. Energy ... 9
1.15.2. Work and heat ... 9
1.16. First Law of Thermodynamics ... 10
1.17. The Perfect Gas ... 11
1.17.1. The characteristic equation of state ... 11
1.17.2. Specific heats ... 12
1.17.3. Joule’s law ... 13
1.17.4. Relationship between two specific heats ... 13
1.17.5. Enthalpy ... 14
1.17.6. Ratio of specific heats ... 15
( v )
( vi )
Chapter Pages
1.18. Steady Flow Energy Equation (S.F.E.E.) ... 16
1.18.1. Energy relations for flow process ... 17
1.19. Limitations of First Law of Thermodynamics ... 18
1.20. Performance of Heat Engine and Reversed Heat Engine ... 18
1.21. Statements of Second Law of Thermodynamics ... 19
1.21.1. Clausius statement ... 19
1.21.2. Kelvin-Planck statement ... 20
1.22. Entropy ... 20
1.22.1. Introduction ... 20
1.22.2. Temperature-entropy diagram ... 20
1.22.3. Characteristics of entropy ... 21
1.23. The Third Law of Thermodynamics ... 21
1.24. Available and Unavailable Energy ... 22
Highlights ... 23
Objective Type Questions ... 25
Theoretical Questions ... 32
2. INTRODUCTION TO INTERNAL COMBUSTION ENGINES 33–84
2.1. Heat Engines ... 33
2.2. Development of I.C. Engines ... 35
2.3. Classification of I.C. Engines ... 35
2.4. Application of I.C. Engines ... 38
2.5. Engine Cycle-Energy Balance ... 39
2.6. Basic Idea of I.C. Engines ... 40
2.7. Different Parts of I.C. Engines ... 41
2.8. Terms Connected with I.C. Engines ... 66
2.9. Working Cycles ... 68
2.10. Indicator Diagram ... 69
2.11. Four Stroke Cycle Engines ... 69
2.12. Two Stroke Cycle Engines ... 75
2.13. Intake for Compression Ignition Engines ... 77
2.14. Comparison of Four Stroke and Two Stroke Cycle Engines ... 78
2.15. Comparison of Spark Ignition (S.I.) and Compression Ignition (C.I.)
Engines ... 79
2.16. Comparison between a Petrol Engine and a Diesel Engine ... 81
2.17. How to Tell a Two Stroke Cycle Engine from a Four Stroke
Cycle Engine ? ... 81
Highlights ... 82
Objective Type Questions ... 83
Theoretical Questions ... 84
3. AIR STANDARD CYCLES 85–161
3.1. Definition of a Cycle ... 85
3.2. Air Standard Efficiency ... 85
3.3. The Carnot Cycle ... 86
3.4. Constant Volume or Otto Cycle ... 94
( vii)
Chapter Pages
3.5. Constant Pressure or Diesel Cycle ... 110
3.6. Dual Combustion Cycle ... 120
3.7. Comparison of Otto, Diesel and Dual Combustion Cycles ... 136
3.7.1. Efficiency versus compression ratio ... 136
3.7.2. For the same compression ratio and the same heat input ... 137
3.7.3. For constant maximum pressure and heat supplied ... 137
3.8. Atkinson Cycle ... 138
3.9. Ericsson Cycle ... 141
3.10. Brayton Cycle ... 142
3.11. Stirling Cycle ... 153
3.12. Miller Cycle ... 155
3.13. Lenoir Cycle ... 156
Highlights ... 158
Objective Type Questions ... 158
Theoretical Questions ... 159
Unsolved Examples ... 160
4. FUEL-AIR AND ACTUAL CYCLES 162–200
4.1. Fuel-air Cycles ... 162
4.1.1. Introduction ... 162
4.1.2. Factors considered for fuel-air cycle calculations ... 162
4.1.3. Assumptions made for fuel-air cycle analysis ... 163
4.1.4. Importance of fuel-air cycle ... 163
4.1.5. Variable specific heats ... 163
4.1.6. Effect of variation of specific heats ... 170
4.1.7. Dissociation ... 171
4.1.8. Thermal efficiency and fuel consumption ... 172
4.1.9. Effect of common engine variables ... 173
4.1.10. Characteristics of constant volume fuel-air cycle ... 178
4.1.11. Combustion charts ... 178
4.1.12. Gas tables ... 178
4.2. Actual Cycles ... 181
4.2.1. Introduction ... 181
4.2.2. Causes of deviation of actual cycles from fuel-air cycles ... 181
4.2.3. Real fuel-air engine cycles ... 181
4.2.4. Difference between real cycle and fuel-air cycle ... 182
4.2.5. Comparison of operations and working media for ‘air cycle’,
fuel-air cycle’ and ‘actual cycle’ of S.I. engines ... 185
Highlights ... 197
Objective Type Questions ... 197
Theoretical Questions ... 198
Unsolved Examples ... 199
5. COMBUSTION IN S.I. ENGINES 201–225
5.1. Introduction ... 201
5.1.1. Definition of combustion ... 201
5.1.2. Ignition limits ... 201
( viii)
Chapter Pages
5.2. Combustion Phenomenon ... 202
5.2.1. Normal combustion ... 202
5.2.2. Abnormal combustion ... 204
5.3. Effect of Engine Variables on Ignition Lag ... 204
5.4. Spark Advance and Factors Affecting Ignition Timing ... 205
5.5. Pre-ignition ... 205
5.6. Detonation ... 208
5.6.1. Introduction ... 208
5.6.2. Process of detonation or knocking ... 208
5.6.3. Theories of detonation ... 210
5.6.4. Effects of detonation ... 210
5.6.5. Factors affecting detonation/knocks ... 210
5.7. Performance Number (PN) ... 211
5.8. Highest Useful Compression Ratio (HUCR) ... 211
5.9. Combustion Chamber Design—S.I. Engines ... 211
5.9.1. Induction swirl ... 212
5.9.2. Squish and tumble ... 213
5.9.3. Quench area ... 213
5.9.4. Turbulence ... 214
5.9.5. Flame propagation ... 215
5.9.6. Swirl ratio ... 215
5.9.7. Surface-to-volume ratio ... 215
5.9.8. Stroke-to-bore ratio ... 216
5.9.9. Compression ratio (C.R.) ... 216
5.10. Some Types of Combustion Chambers ... 218
5.10.1. Divided combustion chambers ... 220
Highlights ... 223
Objective Type Questions ... 224
Theoretical Questions ... 225
6. COMBUSTION IN C.I. ENGINES 226–247
6.1. Introduction ... 226
6.2. Combustion Phenomenon in C.I. Engines ... 227
6.3. Fundamentals of the Combustion Process in Diesel Engines ... 230
6.4. Delay Period (or Ignition Lag) in C.I. Engines ... 234
6.5. Diesel Knock ... 236
6.6. C.I. Engine Combustion Chambers ... 237
6.6.1. Primary considerations in the design of combustion
chambers for C.I. engines ... 237
6.6.2. Basic methods of generating air swirl in C.I. engines
combustion chambers ... 238
6.6.3. Types of combustion chambers ... 240
6.7. Cold Starting of C.I. Engines ... 244
Highlights ... 245
Objective Type Questions ... 246
Theoretical Questions ... 246