Aircraft propulsionPDF电子书下载

1Introduction 1

1.1 History of Airbreathing Jet Engine，a Twentieth Century Invention—The Beginning 1

1.2 Innovations in Aircraft Gas Turbine Engines 4

1.2.1 Multispool Configuration 4

1.2.2 Variable Stator 4

1.2.3 Transonic Compressor 5

1.2.4 Low-Emission Combustor 6

1.2.5 Turbine Cooling 7

1.2.6 Exhaust Nozzles 7

1.2.7 Modern Materials and Manufacturing Techniques 8

1.3 New Engine Concepts 9

1.3.1 Wave Rotor Topping Cycle 9

1.3.1.1 Humphrey Cycle versus Brayton Cycle 9

1.3.2 Pulse Detonation Engine （PDE） 11

1.3.3 Millimeter-Scale Gas Turbine Engines：Triumph of MEMS 11

1.3.4 Combined Cycle Propulsion：Engines from Takeoff to Space 11

1.4 New Vehicles 13

1.5 Summary 14

1.6 Roadmap for the Book 14

References 15

Problems 16

2Compressible Flow with Friction and Heat：A Review 17

2.1 Introduction 17

2.2 A Brief Review of Thermodynamics 18

2.3 Isentropic Process and Isentropic Flow 23

2.4 Conservation Principles for Systems and Control Volumes 23

2.5 Speed of Sound ＆ Mach Number 29

2.6 Stagnation State 32

2.7 Quasi-One-Dimensional Flow 35

2.8 Area-Mach Number Relationship 38

2.9 Sonic Throat 39

2.10 Waves in Supersonic Flow 42

2.11 Normal Shocks 43

2.12 Oblique Shocks 47

2.13 Conical Shocks 52

2.14 Expansion Waves 55

2.15 Frictionless，Constant-Area Duct Flow with Heat Transfer 58

2.16 Adiabatic Flow of a Calorically Perfect Gas in aConstant-Area Duct with Friction 67

2.17 Friction （Drag） Coefficient，Cf and D’Arcy Friction Factor fD 79

2.18 Dimensionless Parameters 80

2.19 Fluid Impulse 83

2.20 Summary of Fluid Impulse 89

References 90

Problems 90

3Engine Thrust and Performance Parameters 97

3.1 Introduction 97

3.1.1 Takeoff Thrust 103

3.2 Installed Thrust—Some Bookkeeping Issues on Thrust and Drag 103

3.3 Engine Thrust Based on the Sum of Component Impulse 108

3.4 Rocket Thrust 110

3.5 Airbreathing Engine Performance Parameters 112

3.5.1 Specific Thrust 112

3.5.2 Specific Fuel Consumption and Specific Impulse 112

3.5.3 Thermal Efficiency 113

3.5.4 Propulsive Efficiency 116

3.5.5 Engine Overall Efficiency and Its Impact on Aircraft Range and Endurance 119

3.6 Summary 121

References 122

Problems 122

4Gas Turbine Engine Cycle Analysis 127

4.1 Introduction 127

4.2 The Gas Generator 127

4.3 Aircraft Gas Turbine Engines 128

4.3.1 The Turbojet Engine 128

4.3.1.1 The Inlet 129

4.3.1.2 The Compressor 133

4.3.1.3 The Burner 139

4.3.1.4 The Turbine 143

4.3.1.5 The Nozzle 151

4.3.1.6 Thermal Efficiency of a Turbojet Engine 158

4.3.1.7 Propulsive Efficiency of a Turbojet Engine 165

4.3.1.8 The Overall Efficiency of a Turbojet Engine 167

4.3.1.9 Performance Evaluation of a Turbojet Engine 167

4.3.2 The Turbojet Engine with an Afterburner 168

4.3.2.1 Introduction 168

4.3.2.2 Analysis 171

4.3.2.3 Optimum Compressor Pressure Ratio for Maximum （Ideal） Thrust Turbojet Engine with Afterburner 174

4.3.3 The Turbofan Engine 179

4.3.3.1 Introduction 179

4.3.3.2 Analysis of a Separate-Exhaust Turbofan Engine 179

4.3.3.3 Thermal Efficiency of a Turbofan Engine 184

4.3.3.4 Propulsive Efficiency of a Turbofan Engine 185

4.4 Analysis of a Mixed-Exhaust Turbofan Engine with an Afterburner 190

4.4.1 Mixer 190

4.4.2 Cycle Analysis 193

4.4.2.1 Solution Procedure 193

4.5 The Turboprop Engine 203

4.5.1 Introduction 203

4.5.2 Cycle Analysis 204

4.5.2.1 The New Parameters 204

4.5.2.2 Design Point Analysis 205

4.5.2.3 Optimum Power Split Between the Propeller and the Jet 209

4.6 Summary 213

References 214

Problems 214

5Aircraft Engine Inlets and Nozzles 225

5.1 Introduction 225

5.2 The Flight Mach Number and Its Impact on Inlet Duct Geometry 226

5.3 Diffusers 227

5.4 An Ideal Diffuser 227

5.5 Real Diffusers and their Stall Characteristics 228

5.6 Subsonic Diffuser Performance 230

5.7 Subsonic Cruise Inlet 234

5.8 Transition Ducts 244

5.9 An Interim Summary for Subsonic Inlets 245

5.10 Supersonic Inlets 246

5.10.1 Isentropic Convergent-Divergent Inlets 246

5.10.2 Methods to Start a Supersonic Convergent-Divergent Inlet 249

5.10.2.1 Overspeeding 250

5.10.2.2 Kantrowitz-Donaldson Inlet 251

5.10.2.3 Variable-Throat Isentropic C-D Inlet 252

5.11 Normal Shock Inlets 254

5.12 External Compression Inlets 256

5.12.1 Optimum Ramp Angles 259

5.12.2 Design and Off-Design Operation 259

5.13 Variable Geometry—External Compression Inlets 261

5.13.1 Variable Ramps 262

5.14 Mixed-Compression Inlets 262

5.15 Supersonic Inlet Types and Their Performance—A Review 264

5.16 Standards for Supersonic Inlet Recovery 265

5.17 Exhaust Nozzle 266

5.18 Gross Thrust 267

5.19 Nozzle Adiabatic Efficiency 267

5.20 Nozzle Total Pressure Ratio 268

5.21 Nozzle Pressure Ratio （NPR） and Critical Nozzle Pressure Ratio （NPRcrit.） 268

5.22 Relation between Nozzle Figures of Merit，ηn and πn 269

5.23 A Convergent Nozzle or a De Laval？ 270

5.24 The Effect of Boundary Layer Formation on Nozzle Internal Performance 272

5.25 Nozzle Exit Flow Velocity Coefficient 272

5.26 Effect of Flow Angularity on Gross Thrust 274

5.27 Nozzle Gross Thrust Coefficient Cfg 277

5.28 Overexpanded Nozzle Flow—Shock Losses 278

5.29 Nozzle Area Scheduling，A8 and A9/A8 281

5.30 Nozzle Exit Area Scheduling，A9/A8 283

5.31 Nozzle Cooling 285

5.32 Thrust Reverser and Thrust Vectoring 287

5.33 Hypersonic Nozzle 292

5.34 Exhaust Mixer and Gross Thrust Gain in a Mixed-Flow Turbofan Engine 294

5.35 Nozzle-Turbine （Structural） Integration 296

5.36 Summary of Exhaust Systems 297

References 298

Problems 300

6Combustion Chambers and Afterburners 308

6.1 Introduction 308

6.2 Laws Governing Mixture of Gases 310

6.3 Chemical Reaction and Flame Temperature 312

6.4 Chemical Equilibrium and Chemical Composition 321

6.4.1 The Law of Mass Action 322

6.4.2 Equilibrium Constant Kp 324

6.5 Chemical Kinetics 332

6.5.1 Ignition and Relight Envelope 333

6.5.2 Reaction Timescale 333

6.5.3 Flammability Limits 335

6.5.4 Flame Speed 337

6.5.5 Flame Stability 339

6.5.6 Spontaneous Ignition Delay Time 344

6.5.7 Combustion-Generated Pollutants 345

6.6 Combustion Chamber 345

6.6.1 Combustion Chamber Total Pressure Loss 347

6.6.2 Combustor Flow Pattern and Temperature Profile 355

6.6.3 Combustor Liner and Its Cooling Methods 356

6.6.4 Combustion Efficiency 359

6.6.5 Some Combustor Sizing and Scaling Laws 360

6.6.6 Afterburner 363

6.7 Combustion-Generated Pollutants 368

6.7.1 Greenhouse Gases，CO2 and H2O 368

6.7.2 Carbon Monoxide，CO，and Unburned Hydrocarbons，UHC 369

6.7.3 Oxides of Nitrogen，NO and NO2 370

6.7.4 Smoke 370

6.7.5 Engine Emission Standards 372

6.7.6 Low-Emission Combustors 373

6.7.7 Impact of NO on the Ozone Layer 377

6.8 Aviation Fuels 379

6.9 Combustion Instability：Screech 382

6.9.1 Screech Damper 383

6.10 Summary 383

References 384

Problems 385

7Axial Compressor Aerodynamics 389

7.1 Introduction 389

7.2 The Geometry 389

7.3 Rotor and Stator Frames of Reference 390

7.4 The Euler Turbine Equation 392

7.5 Axial-Flow Versus Radial-Flow Machines 394

7.6 Axial-Flow Compressors and Fans 395

7.6.1 Definition of Flow Angles 397

7.6.2 Stage Parameters 399

7.6.3 Cascade Aerodynamics 410

7.6.4 Aerodynamic Forces on Compressor Blades 423

7.6.5 Three-Dimensional Flow 430

7.6.5.1 Blade Vortex Design 431

7.6.5.2 Three-Dimensional Losses 442

7.6.5.3 Reynolds Number Effect 446

7.7 Compressor Performance Map 448

7.8 Compressor Instability—Stall and Surge 451

7.9 Multistage Compressors and Their Operating Line 455

7.10 Multistage Compressor Stalling Pressure Rise and Stall Margin 459

7.11 Multistage Compressor Starting Problem 467

7.12 The Effect of Inlet Flow Condition on Compressor Performance 470

7.13 Isometric and Cutaway Views of Axial-Flow Compressor Hardware 473

7.14 Compressor Design Parameters and Principles 475

7.14.1 Blade Design—Blade Selection 478

7.14.2 Compressor Annulus Design 480

7.14.3 Compressor Stall Margin 480

7.15 Summary 488

References 490

Problems 492

8Centrifugal Compressor Aerodynamics 498

8.1 Introduction 498

8.2 Centrifugal Compressors 499

8.3 Radial Diffuser 512

8.4 Inducer 515

8.5 Inlet Guide Vanes （IGVs） and Inducer-less Impellers 518

8.6 Impeller Exit Flow and Blockage Effects 519

8.7 Efficiency and Performance 520

8.8 Summary 522

References 523

Problems 524

9Aerothermodynamics of Gas Turbines 527

9.1 Introduction 527

9.2 Axial-Flow Turbines 527

9.2.1 Optimal Nozzle Exit Swirl Mach Number Mθ2 539

9.2.2 Turbine Blade Losses 542

9.2.2.1 Blade Profile Loss 543

9.2.2.2 Secondary Flow Losses 544

9.2.2.3 Annulus Losses 546

Turbine Rotor Tip Clearance Loss 546

9.2.3 Optimum Solidity 553

9.2.4 Turbine Cooling 557

9.2.4.1 Convective Cooling 561

9.2.4.2 Impingement Cooling 565

9.2.4.3 Film Cooling 567

9.2.4.4 Transpiration Cooling 569

9.3 Turbine Performance Map 569

9.4 The Effect of Cooling on Turbine Efficiency 570

9.5 Turbine Blade Profile Design 572

9.5.1 Angles 572

9.5.2 Other Blade Geometric Parameters 573

9.5.3 Throat Sizing 574

9.5.4 Throat Reynolds Number Reo 574

9.5.5 Turbine Blade Profile Design 575

9.5.6 Blade Vibration and Campbell Diagram 575

9.5.7 Turbine Blade and Disk Material Selection and Design Criteria 576

9.6 Stresses in Turbine Blades and Disks and Useful Life Estimation 579

9.7 Axial-Flow Turbine Design and Practices 582

9.8 Gas Turbine Design Summary 589

9.9 Summary 590

References 591

Problems 593

10Aircraft Engine Component Matching and Off-Design Analysis 598

10.1 Introduction 598

10.2 Engine （Steady-State） Component Matching 599

10.2.1 Engine Corrected Parameters 599

10.2.2 Inlet-Compressor Matching 600

10.2.3 Compressor-Combustor Matching 602

10.2.4 Combustor-Turbine Matching 603

10.2.5 Compressor-Turbine Matching and Gas Generator Pumping Characteristics 605

10.2.5.1 Gas Generator Pumping Characteristics 607

10.2.6 Turbine-Afterburner-（Variable-Geometry） Nozzle Matching 612

10.2.6.1 Fixed-Geometry Convergent Nozzle Matching 614

10.3 Engine Off-Design Analysis 614

10.3.1 Off-Design Analysis of a Turbojet Engine 615

10.3.2 Off-Design Analysis of an Afterburning Turbojet Engine 618

10.3.3 Off-Design Analysis of a Separate-Flow Turbofan （Two-Spool） Engine 621

10.4 Unchoked Nozzles and Other Off-Design Iteration Strategies 625

10.4.1 Unchoked Exhaust Nozzle 625

10.4.2 Unchoked Turbine Nozzle 627

10.4.3 Turbine Efficiency at Off-Design 627

10.4.4 Variable Gas Properties 628

10.5 Summary 628

References 630

Problems 630

11Chemical Rocket and Hypersonic Propulsion 636

11.1 Introduction 636

11.2 From Takeoff to Earth Orbit 638

11.3 Chemical Rockets 639

11.4 Chemical Rocket Applications 639

11.4.1 Launch Vehicles 640

11.4.2 Boost Engines 641

11.4.3 Space Maneuver Engines 641

11.4.4 Attitude Control Rockets 641

11.5 New Parameters in Rocket Propulsion 641

11.6 Thrust Coefficient，CF 644

11.7 Characteristic Velocity，c 647

11.8 Flight Performance 649

11.9 Multistage Rockets 657

11.10 Propulsive and Overall Efficiencies 659

11.11 Chemical Rocket Combustion Chamber 661

11.11.1 Liquid Propellant Combustion Chambers 661

11.11.1.1 Some Design Guidelines for Injector Plate 666

11.11.1.2 Combustion Instabilities 666

11.11.2 Solid Propellant Combustion Chambers 667

11.12 Thrust Chamber Cooling 672

11.12.1 Liquid Propellant Thrust Chambers 673

11.12.2 Cooling of Solid Propellant Thrust Chambers 678

11.13 Combustor Volume and Shape 679

11.14 Rocket Nozzles 679

11.14.1 Multiphase Flow in Rocket Nozzles 682

11.14.2 Flow Expansion in Rocket Nozzles 691

11.14.3 Thrust Vectoring Nozzles 692

11.15 High-Speed Airbreathing Engines 692

11.15.1 Supersonic Combustion Ramjet 698

11.15.1.1 Inlet Analysis 699

11.15.1.2 Scramjet Combustor 700

11.15.1.3 Scramjet Nozzle 702

11.16 Rocket-Based Airbreathing Propulsion 702

11.17 Summary 703

References 704

Problems 704

Appendices 707

A.U.S.Standard Atmosphere 708

B.Isentropic Table 713

C.Normal Shock Table 730

D.Rayleigh Flow 743

E.Fanno Flow 752

F.Prandtl-Meyer Function and Mach Angle 761

G.Oblique Shock Charts 764

H.Conical Shock Charts 769

I.Cascade Data 772

J.Websites 778

Index 779