Internal combustion engine fundamentalsPDF电子书下载

Chapter 1 Engine Types and Their Operation 1

1.1 Introduction and Historical Perspective 1

1.2 Engine Classifications 7

1.3 Engine Operating Cycles 9

1.4 Engine Components 12

1.5 Spark-Ignition Engine Operation 15

1.6 Examples of Spark-Ignition Engines 19

1.7 Compression-Ignition Engine Operation 25

1.8 Examples of Diesel Engines 31

1.9 Stratified-Charge Engines 37

Chapter 2 Engine Design and Operating Parameters 42

2.1 Important Engine Characteristics 42

2.2 Geometrical Properties of Reciprocating Engines 43

2.3 Brake Torque and Power 45

2.4 Indicated Work Per Cycle 46

2.5 Mechanical Efficiency 48

2.6 Road-Load Power 49

2.7 Mean Effective Pressure 50

2.8 Specific Fuel Consumption and Efficiency 51

2.9 Air/Fuel and Fuel/Air Ratios 53

2.10 Volumetric Efficiency 53

2.11 Engine Specific Weight and Specific Volume 54

2.12 Correction Factors for Power and Volumetric Efficiency 54

2.13 Specific Emissions and Emissions Index 56

2.14 Relationships between Performance Parameters 56

2.15 Engine Design and Performance Data 57

Chapter 3 Thermochemistry of Fuel-Air Mixtures 62

3.1 Characterization of Flames 62

3.2 Ideal Gas Model 64

3.3 Composition of Air and Fuels 64

3.4 Combustion Stoichiometry 68

3.5 The First Law of Thermodynamics and Combustion 72

3.5.1 Energy and Enthalpy Balances 72

3.5.2 Enthalpies of Formation 76

3.5.3 Heating Values 78

3.5.4 Adiabatic Combustion Processes 80

3.5.5 Combustion Efficiency of an Internal Combustion Engine 81

3.6 The Second Law of Thermodynamics Applied to Combustion 83

3.6.1 Entropy 83

3.6.2 Maximum Work from an Internal Combustion Engine and Efficiency 83

3.7 Chemically Reacting Gas Mixtures 85

3.7.1 Chemical Equilibrium 86

3.7.2 Chemical Reaction Rates 92

Chapter 4 Properties of Working Fluids 100

4.1 Introduction 100

4.2 Unburned Mixture Composition 102

4.3 Gas Property Relationships 107

4.4 A Simple Analytic Ideal Gas Model 109

4.5 Thermodynamic Charts 112

4.5.1 Unburned Mixture Charts 112

4.5.2 Burned Mixture Charts 116

4.5.3 Relation between Unburned and Burned Mixture Charts 123

4.6 Tables of Properties and Composition 127

4.7 Computer Routines for Property and Composition Calculations 130

4.7.1 Unburned Mixtures 130

4.7.2 Burned Mixtures 135

4.8 Transport Properties 141

4.9 Exhaust Gas Composition 145

4.9.1 Species Concentration Data 145

4.9.2 Equivalence Ratio Determination from Exhaust Gas Constituents 148

4.9.3 Effects of Fuel/Air Ratio Nonuniformity 152

4.9.4 Combustion Inefficiency 154

Chapter 5 Ideal Models of Engine Cycles 161

5.1 Introduction 161

5.2 Ideal Models of Engine Processes 162

5.3 Thermodynamic Relations for Engine Processes 164

5.4 Cycle Analysis with Ideal Gas Working Fluid with c v and c p Constant 169

5.4.1 Constant-Volume Cycle 169

5.4.2 Limited- and Constant-Pressure Cycles 172

5.4.3 Cycle Comparison 173

5.5 Fuel-Air Cycle Analysis 177

5.5.1 SI Engine Cycle Simulation 178

5.5.2 CI Engine Cycle Simulation 180

5.5.3 Results of Cycle Calculations 181

5.6 Overexpanded Engine Cycles 183

5.7 Availability Analysis of Engine Processes 186

5.7.1 Availability Relationships 186

5.7.2 Entropy Changes in Ideal Cycles 188

5.7.3 Availability Analysis of Ideal Cycles 189

5.7.4 Effect of Equivalence Ratio 192

5.8 Comparison with Real Engine Cycles 193

Chapter 6 Gas Exchange Processes 205

6.1 Inlet and Exhaust Prccesses in the Four-Stroke Cycle 206

6.2 Volumetric Efficiency 209

6.2.1 Quasi-Static Effects 209

6.2.2 Combined Quasi-Static and Dynamic Effects 212

6.2.3 Variation with Speed，and Valve Area，Lift，and Timing 216

6.3 Flow Through Valves 220

6.3.1 Poppet Valve Geometry and Timing 220

6.3.2 Flow Rate and Discharge Coefficients 225

6.4 Residual Gas Fraction 230

6.5 Exhaust Gas Flow Rate and Temperature Variation 231

6.6 Scavenging in Two-Stroke Cycle Engines 235

6.6.1 Two-Stroke Engine Configurations 235

6.6.2 Scavenging Parameters and Models 237

6.6.3 Actual Scavenging Processes 240

6.7 Flow Through Ports 245

6.8 Supercharging and Turbocharging 248

6.8.1 Methods of Power Boosting 248

6.8.2 Basic Relationships 249

6.8.3 Compressors 255

6.8.4 Turbines 263

6.8.5 Wave-Compression Devices 270

Chapter 7 SI Engine Fuel Metering and Manifold Phenomena 279

7.1 Spark-Ignition Engine Mixture Requirements 279

7.2 Carburetors 282

7.2.1 Carburetor Fundamentals 282

7.2.2 Modern Carburetor Design 285

7.3 Fuel-Injection Systems 294

7.3.1 Multipoint Port Injection 294

7.3.2 Single-Point Throttle-Body Injection 299

7.4 Feedback Systems 301

7.5 Flow Past Throttle Plate 304

7.6 Flow in Intake Manifolds 308

7.6.1 Design Requirements 308

7.6.2 Air-Flow Phenomena 309

7.6.3 Fuel-Flow Phenomena 314

Chapter 8 Charge Motion within the Cylinder 326

8.1 Intake Jet Flow 326

8.2 Mean Velocity and Turbulence Characteristics 330

8.2.1 Definitions 330

8.2.2 Application to Engine Velocity Data 336

8.3 Swirl 342

8.3.1 Swirl Measurement 343

8.3.2 Swirl Generation during Induction 345

8.3.3 Swirl Modification within the Cylinder 349

8.4 Squish 353

8.5 Prechamber Engine Flows 357

8.6 Crevice Flows and Blowby 360

8.7 Flows Generated by Piston-Cylinder Wall Interaction 365

Chapter 9 Combustion in Spark-Ignition Engines 371

9.1 Essential Features of Process 371

9.2 Thermodynamic Analysis of SI Engine Combustion 376

9.2.1 Burned and Unburned Mixture States 376

9.2.2 Analysis of Cylinder Pressure Data 383

9.2.3 Combustion Process Characterization 389

9.3 Flame Structure and Speed 390

9.3.1 Experimental Observations 390

9.3.2 Flame Structure 395

9.3.3 Laminar Burning Speeds 402

9.3.4 Flame Propagation Relations 406

9.4 Cyclic Variations in Combustion，Partial Burning，and Misfire 413

9.4.1 Observations and Definitions 413

9.4.2 Causes of Cycle-by-Cycle and Cylinder-to-Cylinder Variations 419

9.4.3 Partial Burning，Misfire，and Engine Stability 424

9.5 Spark Ignition 427

9.5.1 Ignition Fundamentals 427

9.5.2 Conventional Ignition Systems 437

9.5.3 Alternative Ignition Approaches 443

9.6 Abnormal Combustion：Knock and Surface Ignition 450

9.6.1 Description of Phenomena 450

9.6.2 Knock Fundamentals 457

9.6.3 Fuel Factors 470

Chapter 10 Combustion in Compression-Ignition Engines 491

10.1 Essential Features of Process 491

10.2 Types of Diesel Combustion Systems 493

10.2.1 Direct-Injection Systems 493

10.2.2 Indirect-Injection Systems 494

10.2.3 Comparison of Different Combustion Systems 495

10.3 Phenomenological Model of Compression-Ignition Engine Combustion 497

10.3.1 Photographic Studies of Engine Combustion 497

10.3.2 Combustion in Direct-Injection，Multispray Systems 503

10.3.3 Application of Model to Other Combustion Systems 506

10.4 Analysis of Cylinder Pressure Data 508

10.4.1 Combustion Efficiency 509

10.4.2 Direct-Injection Engines 509

10.4.3 Indirect-Injection Engines 514

10.5 Fuel Spray Behavior 517

10.5.1 Fuel Injection 517

10.5.2 Overall Spray Structure 522

10.5.3 Atomization 525

10.5.4 Spray Penetration 529

10.5.5 Droplet Size Distribution 532

10.5.6 Spray Evaporation 535

10.6 Ignition Delay 539

10.6.1 Definition and Discussion 539

10.6.2 Fuel Ignition Quality 541

10.6.3 Autoignition Fundamentals 542

10.6.4 Physical Factors Affecting Delay 546

10.6.5 Effect of Fuel Properties 550

10.6.6 Correlations for Ignition Delay in Engines 553

10.7 Mixing-Controlled Combustion 555

10.7.1 Background 555

10.7.2 Spray and Flame Structure 555

10.7.3 Fuel-Air Mixing and Burning Rates 558

Chapter 11 Pollutant Formation and Control 567

11.1 Nature and Extent of Problem 567

11.2 Nitrogen Oxides 572

11.2.1 Kinetics of NO Formation 572

11.2.2 Formation of NO2 577

11.2.3 NO Formation in Spark-Ignition Engines 578

11.2.4 NOx Formation in Compression-Ignition Engines 586

11.3 Carbon Monoxide 592

11.4 Unburned Hydrocarbon Emissions 596

11.4.1 Background 596

11.4.2 Flame Quenching and Oxidation Fundamentals 599

11.4.3 HC Emissions from Spark-Ignition Engines 601

11.4.4 Hydrocarbon Emission Mechanisms in Diesel Engines 620

11.5 Particulate Emissions 626

11.5.1 Spark-Ignition Engine Particulates 626

11.5.2 Characteristics of Diesel Particulates 626

11.5.3 Particulate Distribution within the Cylinder 631

11.5.4 Soot Formation Fundamentals 635

11.5.5 Soot Oxidation 642

11.5.6 Adsorption and Condensation 646

11.6 Exhaust Gas Treatment 648

11.6.1 Available Options 648

11.6.2 Catalytic Converters 649

11.6.3 Thermal Reactors 657

11.6.4 Particulate Traps 659

Chapter 12 Engine Heat Transfer 668

12.1 Importance of Heat Transfer 668

12.2 Modes of Heat Transfer 670

12.2.1 Conduction 670

12.2.2 Convection 670

12.2.3 Radiation 671

12.2.4 Overall Heat-Transfer Process 671

12.3 Heat Transfer and Engine Energy Balance 673

12.4 Convective Heat Transfer 676

12.4.1 Dimensional Analysis 676

12.4.2 Correlations for Time-Averaged Heat Flux 677

12.4.3 Correlations for Instantaneous Spatial Average Coefficients 678

12.4.4 Correlations for Instantaneous Local Coefficients 681

12.4.5 Intake and Exhaust System Heat Transfer 682

12.5 Radiative Heat Transfer 683

12.5.1 Radiation from Gases 683

12.5.2 Flame Radiation 684

12.5.3 Prediction Formulas 688

12.6 Measurements of Instantaneous Heat-Transfer Rates 689

12.6.1 Measurement Methods 689

12.6.2 Spark-Ignition Engine Measurements 690

12.6.3 Diesel Engine Measurements 692

12.6.4 Evaluation of Heat-Transfer Correlations 694

12.6.5 Boundary-Layer Behavior 697

12.7 Thermal Loading and Component Temperatures 698

12.7.1 Component Temperature Distributions 698

12.7.2 Effect of Engine Variables 701

Chapter 13 Eng ne Friction and Lubrication 712

13.1 Background 712

13.2 Definitions 714

13.3 Friction Fundamentals 715

13.3.1 Lubricated Friction 715

13.3.2 Turbulent Dissipation 719

13.3.3 Total Friction 719

13.4 Measurement Methods 719

13.5 Engine Friction Data 722

13.5.1 SI Engines 722

13.5.2 Diesel Engines 724

13.6 Engine Friction Components 725

13.6.1 Motored Engine Breakdown Tests 725

13.6.2 Pumping Friction 726

13.6.3 Piston Assembly Friction 729

13.6.4 Crankshaft Bearing Friction 734

13.6.5 Valve Train Friction 737

13.7 Accessory Power Requirements 739

13.8 Lubrication 740

13.8.1 Lubrication System 740

13.8.2 Lubricant Requirements 741

Chapter 14 Modeling Real Engine Flow and Combustion Processes 748

14.1 Purpose and Classification of Models 748

14.2 Governing Equations for Open Thermodynamic System 750

14.2.1 Conservation of Mass 750

14.2.2 Conservation of Energy 751

14.3 Intake and Exhaust Flow Models 753

14.3.1 Background 753

14.3.2 Quasi-Steady Flow Models 753

14.3.3 Filling and Emptying Methods 754

14.3.4 Gas Dynamic Models 756

14.4 Thermodynamic-Based In-Cylinder Models 762

14.4.1 Background and Overall Model Structure 762

14.4.2 Spark-Ignition Engine Models 766

14.4.3 Direct-Injection Engine Models 778

14.4.4 Prechamber Engine Models 784

14.4.5 Multicylinder and Complex Engine System Models 789

14.4.6 Second Law Analysis of Engine Processes 792

14.5 Fluid-Mechanic-Based Multidimensional Models 797

14.5.1 Basic Approach and Governing Equations 797

14.5.2 Turbulence Models 800

14.5.3 Numerical Methodology 803

14.5.4 Flow Field Predictions 807

14.5.5 Fuel Spray Modeling 813

14.5.6 Combustion Modeling 816

Chapter 15 Engine Operating Characteristics 823

15.1 Engine Performance Parameters 823

15.2 Indicated and Brake Power and MEP 824

15.3 Operating Variables That Affect SI Engine Performance，Efficiency，and Emissions 827

15.3.1 Spark Timing 827

15.3.2 Mixture Composition 829

15.3.3 Load and Speed 839

15.3.4 Compression Ratio 841

15.4 SI Engine Combustion Chamber Design 844

15.4.1 Design Objectives and Options 844

15.4.2 Factors That Control Combustion 846

15.4.3 Factors That Control Performance 850

15.4.4 Chamber Octane Requirement 852

15.4.5 Chamber Optimization Strategy 857

15.5 Variables That Affect CI Engine Performance，Efficiency，and Emissions 858

15.5.1 Load and Speed 858

15.5.2 Fuel-Injection Parameters 863

15.5.3 Air Swirl and Bowl-in-Piston Design 866

15.6 Supercharged and Turbocharged Engine Performance 869

15.6.1 Four-Stroke Cycle SI Engines 869

15.6.2 Four-Stroke Cycle CI Engines 874

15.6.3 Two-Stroke Cycle SI Engines 881

15.6.4 Two-Stroke Cycle CI Engines 883

15.7 Engine Performance Summary 886

Appendixes 899

A Unit Conversion Factors 899

B Ideal Gas Relationships 902

B.1 Ideal Gas Law 902

B.2 The Mole 903

B.3 Thermodynamic Properties 903

B.4 Mixtures of Ideal Gases 905

C Equations for Fluid Flow through a Restriction 906

C.1 Liquid Flow 907

C.2 Gas Flow 907

D Data on Working Fluids 911

Index 917