Aircraft Propulsion

Saeed Farokhi, The University of Kansas, USA

Preface to the Second Edition xvii Preface xix Nomenclature xxiii 1 Introduction 1 1.1 History of the Airbreathing Jet Engine, a Twentieth-Century Invention The Beginning 1 1.2 Innovations in Aircraft Gas Turbine Engines 4 1.3 New Engine Concepts 10 1.4 New Vehicles 16 1.5 Summary 16 1.6 Roadmap for the Second Edition 18 References 19 Problems 20 2 Compressible Flow with Friction and Heat: A Review 21 2.1 Introduction 21 2.2 A Brief Review of Thermodynamics 22 2.3 Isentropic Process and Isentropic Flow 27 2.4 Conservation Principles for Systems and Control Volumes 28 2.5 Speed of Sound & Mach Number 35 2.6 Stagnation State 38 2.7 Quasi-One-Dimensional Flow 41 2.8 Area Mach Number Relationship 44 2.9 Sonic Throat 45 2.10 Waves in Supersonic Flow 49 2.11 Normal Shocks 50 2.12 Oblique Shocks 54 2.13 Conical Shocks 60 2.14 Expansion Waves 63 2.15 Frictionless, Constant-Area Duct Flow with Heat Transfer 67 2.16 Adiabatic Flow of a Calorically Perfect Gas in a Constant-Area Duct with Friction 77 2.17 Friction (Drag) Coefficient Cf and D Arcy Friction Factor fD 91 2.18 Dimensionless Parameters 91 2.19 Fluid Impulse 95 2.20 Summary of Fluid Impulse 102 References 103 Problems 103 3 Engine Thrust and Performance Parameters 113 3.1 Introduction 113 3.2 Installed Thrust Some Bookkeeping Issues on Thrust and Drag 119 3.3 Engine Thrust Based on the Sum of Component Impulse 124 3.4 Rocket Thrust 128 3.5 Airbreathing Engine Performance Parameters 129 3.6 Modern Engines, Their Architecture and Some Performance Characteristics 140 3.7 Summary 143 References 144 Problems 144 4 Gas Turbine Engine Cycle Analysis 151 4.1 Introduction 151 4.2 The Gas Generator 151 4.3 Aircraft Gas Turbine Engines 152 4.4 Analysis of a Mixed-Exhaust Turbofan Engine with an Afterburner 225 4.5 The Turboprop Engine 241 4.6 Summary 260 References 261 Problems 261 5 General Aviation and Uninhabited Aerial Vehicle Propulsion System 283 5.1 Introduction 283 5.2 Cycle Analysis 284 5.3 Power and Efficiency 293 5.4 Engine Components and Classifications 295 5.5 Scaling of Aircraft Reciprocating Engines 300 5.6 Aircraft Engine Systems 308 5.7 Electric Engines 314 5.8 Propellers and Reduction Gears 319 References 322 Problems 324 6 Aircraft Engine Inlets and Nozzles 327 6.1 Introduction 327 6.2 The Flight Mach Number and Its Impact on Inlet Duct Geometry 328 6.3 Diffusers 329 6.4 An Ideal Diffuser 330 6.5 Real Diffusers and Their Stall Characteristics 331 6.6 Subsonic Diffuser Performance 333 6.7 Subsonic Cruise Inlet 338 6.8 Transition Ducts 348 6.9 An Interim Summary for Subsonic Inlets 349 6.10 Supersonic Inlets 350 6.11 Normal Shock Inlets 359 6.12 External Compression Inlets 362 6.13 Variable Geometry External Compression Inlets 368 6.14 Mixed-Compression Inlets 368 6.15 Supersonic Inlet Types and Their Performance A Review 370 6.16 Standards for Supersonic Inlet Recovery 371 6.17 Exhaust Nozzle 373 6.18 Gross Thrust 373 6.19 Nozzle Adiabatic Efficiency 373 6.20 Nozzle Total Pressure Ratio 374 6.21 Nozzle Pressure Ratio (NPR) and Critical Nozzle Pressure Ratio (NPRcrit.) 374 6.22 Relation Between Nozzle Figures of Merit, n and n 376 6.23 A Convergent Nozzle or a De Laval? 376 6.24 The Effect of Boundary Layer Formation on Nozzle Internal Performance 379 6.25 Nozzle Exit Flow Velocity Coefficient 379 6.26 Effect of Flow Angularity on Gross Thrust 381 6.27 Nozzle Gross Thrust Coefficient Cfg 385 6.28 Overexpanded Nozzle Flow Shock Losses 386 6.29 Nozzle Area Scheduling, A8 and A9/A8 389 6.30 Nozzle Exit Area Scheduling, A9/A8 391 6.31 Nozzle Cooling 394 6.32 Thrust Reverser and Thrust Vectoring 396 6.33 Hypersonic Nozzle 401 6.34 Exhaust Mixer and Gross Thrust Gain in a Mixed-Flow Turbofan Engine 404 6.35 Noise 406 6.36 Nozzle-Turbine (Structural) Integration 409 6.37 Summary of Exhaust Systems 410 References 411 Problems 413 7 Combustion Chambers and Afterburners 429 7.1 Introduction 429 7.2 Laws Governing Mixture of Gases 431 7.3 Chemical Reaction and Flame Temperature 434 7.4 Chemical Equilibrium and Chemical Composition 445 7.5 Chemical Kinetics 459 7.6 Combustion Chamber 473 7.7 Combustion-Generated Pollutants 498 7.8 Aviation Fuels 509 7.9 Alternative Drop-In Jet Fuels (AJFs) 513 7.10 Combustion Instability: Screech and Rumble 515 7.11 Summary 516 References 516 Problems 518 8 Axial Compressor Aerodynamics 525 8.1 Introduction 525 8.2 The Geometry 525 8.3 Rotor and Stator Frames of Reference 526 8.4 The Euler Turbine Equation 529 8.5 Axial-Flow Versus Radial-Flow Machines 530 8.6 Axial-Flow Compressors and Fans 532 8.7 Compressor Performance Map 593 8.8 Compressor Instability Stall and Surge 595 8.9 Multistage Compressors and Their Operating Line 599 8.10 Multistage Compressor Stalling Pressure Rise and Stall Margin 604 8.11 Multistage Compressor Starting Problem 612 8.12 The Effect of Inlet Flow Condition on Compressor Performance 615 8.13 Isometric and Cutaway Views of Axial-Flow Compressor Hardware 620 8.14 Compressor Design Parameters and Principles 620 8.15 Summary 636 References 638 Problems 640 9 Centrifugal Compressor Aerodynamics 651 9.1 Introduction 651 9.2 Centrifugal Compressors 652 9.3 Radial Diffuser 666 9.4 Inducer 670 9.5 Inlet Guide Vanes (IGVs) and Inducer-Less Impellers 673 9.6 Impeller Exit Flow and Blockage Effects 673 9.7 Efficiency and Performance 674 9.8 Summary 677 References 678 Problems 678 10 Aerothermo-dynamics of Gas Turbines 685 10.1 Introduction 685 10.2 Axial-Flow Turbines 685 10.3 Turbine Performance Map 733 10.4 The Effect of Cooling on Turbine Efficiency 734 10.5 Turbine Blade Profile Design 735 10.6 Stresses in Turbine Blades and Disks and Useful Life Estimation 743 10.7 Axial-Flow Turbine Design and Practices 746 10.8 Gas Turbine Design Summary 754 10.9 Summary 755 References 757 Problems 759 11 Aircraft Engine Component Matching and Off-Design Analysis 767 11.1 Introduction 767 11.2 Engine (Steady-State) Component Matching 768 11.3 Engine Off-Design Analysis 785 11.4 Unchocked Nozzles and Other Off-Design Iteration Strategies 798 11.5 Principles of Engine Performance Testing 802 11.6 Summary 810 References 812 Problems 813 12 Chemical Rocket and Hypersonic Propulsion 821 12.1 Introduction 821 12.2 From Takeoff to Earth Orbit 823 12.3 Chemical Rockets 824 12.4 Chemical Rocket Applications 826 12.5 New Parameters in Rocket Propulsion 827 12.6 Thrust Coefficient, CF 830 12.7 Characteristic Velocity, c* 833 12.8 Flight Performance 835 12.9 Multistage Rockets 845 12.10 Propulsive and Overall Efficiencies 847 12.11 Chemical Rocket Combustion Chamber 849 12.12 Thrust Chamber Cooling 862 12.13 Combustor Volume and Shape 869 12.14 Rocket Nozzles 870 12.15 High-Speed Airbreathing Engines 884 12.16 Rocket-Based Airbreathing Propulsion 895 12.17 Summary 897 References 898 Problems 899 Appendices 903 A. U.S. Standard Atmosphere 905 B. Isentropic Table 909 C. Normal Shock Table 927 D. Rayleigh Flow 941 E. Fanno Flow 951 F. Prandtl Meyer Function and Mach Angle 961 G. Oblique Shock Charts 965 H. Conical Shock Charts 971 I. Cascade Data 975 J. Web Sites 981 K. 10-Minute Quizzes 983 L. Some Rules of Thumb and Trends in Aircraft Propulsion 1001 Index