Introduction to Aerospace Engineering with a Flight Test Perspective

Stephen Corda has BS, MS, and PhD degrees in Aerospace Engineering from the University of Maryland and an Aeronautics Diploma from the Von Karman Institute for Fluid Dynamics in Belgium. The material for this textbook is derived from the author’s 30 years of experience as an aerospace engineer, flight test engineer, flight research pilot, and educator at the NASA Armstrong Flight Research Center, The Johns Hopkins University Applied Physics Laboratory, the U.S. Air Force Test Pilot School, the U.S. Naval Academy, the University of Tennessee Space Institute, and Virgin Galactic-The Spaceship Company. He is currently an aerospace engineering consultant, living in California.

About the Author xv

Series Preface xvii

Preface xix

About the Companion website xxi

1 First Flights 1

1.1 Introduction 2

1.1.1 Organization of the Book 3

1.1.2 FTT: Your Familiarization Flight 4

1.2 Aircraft 12

1.2.1 Classification of Aircraft 12

1.2.2 The Airplane 13

1.2.3 Rotorcraft: the Helicopter 26

1.2.4 Lighter-Than-Air Aircraft: Balloon and Airship 35

1.2.5 The Unmanned Aerial Vehicle 43

1.3 Spacecraft 45

1.3.1 Classification of Spacecraft 46

1.3.2 Parts of a Spacecraft 52

1.3.3 Unmanned Spacecraft 57

1.3.4 Manned Spacecraft 69

1.3.5 Space Access Systems and Vehicles 77

References 96

2 Introductory Concepts 98

2.1 Introduction 98

2.2 Introductory Mathematical Concepts 99

2.2.1 Units and Unit Systems 99

2.2.2 Measurement and Numerical Uncertainty 107

2.2.3 Scalars and Vectors 113

2.3 Introductory Aerospace Engineering Concepts 114

2.3.1 Aircraft Body Axes 115

2.3.2 Angle-of-Attack and Angle-of-Sideslip 116

2.3.3 Aircraft Stability Axes 118

2.3.4 Aircraft Location Numbering System 119

2.3.5 The Free-Body Diagram and the Four Forces 120

2.3.6 FTT: the Trim Shot 125

2.3.7 Mach Number and the Regimes of Flight 129

2.3.8 The Flight Envelope 132

2.3.9 The V-n Diagram 144

2.3.10 Aircraft Weight and Balance 150

2.3.11 Aerospace Vehicle Designations and Naming 157

2.4 Introductory Flight Test Concepts 161

2.4.1 What is a Flight Test? 161

2.4.2 The Flight Test Process 165

2.4.3 Flight Test Techniques 169

2.4.4 Roles of Test Pilot, Flight Test Engineer, and Flight Test Analyst 173

2.4.5 Flight Test Safety and Risk Assessment 174

References 177

Problems 178

3 Aerodynamics 181

3.1 Introduction 182

3.2 Fundamental Physical Properties of a Fluid 183

3.2.1 The Fluid Element 183

3.2.2 Thermodynamic Properties of a Fluid 184

3.2.3 Kinematic Properties of a Flow 186

3.2.4 Streamlines, Pathlines, and Flow Visualization 187

3.2.5 FTT: In-Flight Flow Visualization 188

3.2.6 Transport Properties of a Fluid 192

3.3 Types of Aerodynamic Flows 195

3.3.1 Continuum and Non-Continuum Flows 195

3.3.2 Steady and Unsteady Flows 196

3.3.3 Incompressible and Compressible Flows 197

3.3.4 Inviscid and Viscous Flows 198

3.4 Similarity Parameters 201

3.4.1 Mach Number 202

3.4.2 Reynolds Number 203

3.4.3 Pressure Coefficient 205

3.4.4 Force and Moment Coefficients 205

3.4.5 Ratio of Specific Heats 206

3.4.6 Prandtl Number 206

3.4.7 Other Similarity Parameters 206

3.4.8 Summary of Similarity Parameters 212

3.5 A Brief Review of Thermodynamics 213

3.5.1 Thermodynamic System and State 213

3.5.2 Connecting the Thermodynamic State: The Equation of State 215

3.5.3 Additional Thermodynamic Properties: Internal Energy, Enthalpy, and Entropy 223

3.5.4 Work and Heat 224

3.5.5 The Laws of Thermodynamics 229

3.5.6 Specific Heats of an Ideal Gas 232

3.5.7 Isentropic Flow 236

3.6 Fundamental Equations of Fluid Motion 239

3.6.1 Conservation of Mass: The Continuity Equation 239

3.6.2 Newton’s Second Law: The Momentum Equation 241

3.6.3 Conservation of Energy: The Energy Equation 246

3.6.4 Summary of the Governing Equations of Fluid Flow 247

3.7 Aerodynamic Forces and Moments 248

3.7.1 Lift 251

3.7.2 Drag 258

3.7.3 GTT: Drag Cleanup 269

3.7.4 GTT: Wind Tunnel Testing 270

3.7.5 GTT: Computational Fluid Dynamics 286

3.7.6 FTT: Lift and Drag in Steady, Gliding Flight 292

3.8 Two-Dimensional Lifting Shapes: Airfoils 298

3.8.1 Airfoil Construction and Nomenclature 303

3.8.2 Airfoil Numbering Systems 305

3.8.3 Airfoil Lift, Drag, and Pitching Moment 307

3.8.4 Pressure Coefficient 308

3.8.5 Airfoil Lift, Drag, and Moment Curves 310

3.8.6 Data for Selected Symmetric and Cambered Airfoils 315

3.8.7 Comparison of Symmetric and Cambered Airfoils 322

3.9 Three-Dimensional Aerodynamics: Wings 325

3.9.1 Finite Wings 325

3.9.2 Lift and Drag Curves of Finite Wings 338

3.9.3 High-Lift Devices 341

3.9.4 FTT: Aeromodeling 347

3.9.5 Wings in Ground Effect 354

3.10 Compressible, Subsonic and Transonic Flows 359

3.10.1 The Speed of Sound 360

3.10.2 The Critical Mach Number and Drag Divergence 363

3.10.3 Compressibility Corrections 365

3.10.4 The "Sound Barrier" 370

3.10.5 Breaking the Sound Barrier: the Bell X-1 and the Miles M. 52 371

3.11 Supersonic Flow 377

3.11.1 Isentropic Flow Relations 378

3.11.2 Shock and Expansion Waves 381

3.11.3 FTT: Visualizing Shock waves in Flight 387

3.11.4 Sonic Boom 391

3.11.5 Lift and Drag of Supersonic Airfoils 396

3.11.6 Supercritical Airfoils 399

3.11.7 Wings for Supersonic Flight 401

3.11.8 Transonic and Supersonic Area Rule 417

3.11.9 Internal Supersonic Flows 422

3.12 Viscous Flow 429

3.12.1 Skin Friction and Shearing Stress 430

3.12.2 Boundary Layers 431

3.12.3 Skin Friction Drag 440

3.12.4 Aerodynamic Stall and Departure 444

3.12.5 FTT: Stall, Departure, and Spin Flight Testing 458

3.13 Hypersonic Flow 463

3.13.1 Hypersonic Vehicles 464

3.13.2 Effects of High Mach Number 467

3.13.3 Effects of High Temperature 470

3.13.4 Viscous Hypersonic Flow 473

3.13.5 Effects of Low Density 476

3.13.6 Approximate Analyses of Inviscid Hypersonic Flow 476

3.13.7 Aerodynamic Heating 481

3.13.8 FTT: Hypersonic Flight Testing 485

3.14 Summary of Lift and Drag Theories 495

References 497

Problems 500

4 Propulsion 504

4.1 Introduction 504

4.1.1 The Concept of Propulsive Thrust 505

4.1.2 Engine Station Numbering 509

4.2 Propulsive Flows with Heat Addition and Work 511

4.3 Derivation of the Thrust Equations 513

4.3.1 Force Accounting 514

4.3.2 Uninstalled Thrust for the Rocket Engine 515

4.3.3 Uninstalled Thrust for the Ramjet and Turbojet 518

4.3.4 Installed Thrust for an Air-Breathing Engine 520

4.3.5 Thrust Equation for a Propeller 521

4.4 Thrust and Power Curves for Propeller-Driven and Jet Engines 525

4.4.1 FTT: In-Flight Thrust Measurement 526

4.5 Air-Breathing Propulsion 531

4.5.1 Air-Breathing Propulsion Performance Parameters 532

4.5.2 The Ramjet 538

4.5.3 The Gas Generator 542

4.5.4 The Turbojet Engine 548

4.5.5 The Turbofan Engine 555

4.5.6 The Turboprop and Turboshaft Engines 558

4.5.7 More about Inlets and Nozzles for Air-Breathing Engines 560

4.5.8 The Reciprocating, Piston Engine–Propeller Combination 570

4.5.9 Summary of Thermodynamic Cycles for Air-Breathing Engines 585

4.5.10 GTT: the Engine Test Cell and Test Stand 585

4.5.11 FTT: Flying Engine Testbeds 588

4.6 Rocket Propulsion 589

4.6.1 Thrust Chamber Thermodynamics 590

4.6.2 Rocket Propulsion Performance Parameters 592

4.6.3 Liquid-Propellant Rocket Propulsion 601

4.6.4 Solid-Propellant Rocket Propulsion 604

4.6.5 Hybrid-Propellant Rocket Propulsion 607

4.6.6 Types of Rocket Nozzles 611

4.7 Other Types of Non-Air-Breathing Propulsion 613

4.7.1 Nuclear Rocket Propulsion 614

4.7.2 Electric Spacecraft Propulsion 616

4.7.3 Solar Propulsion 623

4.8 Other Types of Air-Breathing Propulsion 627

4.8.1 The Scramjet 627

4.8.2 Combined Cycle Propulsion 629

4.8.3 Unsteady Wave Propulsion 630

References 634

Problems 635

5 Performance 637

5.1 Introduction 638

5.2 Altitude Definitions 641

5.3 Physical Description of the Atmosphere 644

5.3.1 Chemical Composition of the Atmosphere 645

5.3.2 Layers of the Atmosphere 646

5.3.3 GTT: Cabin Pressurization Test 649

5.4 Equation of Fluid Statics: The Hydrostatic Equation 651

5.5 The Standard Atmosphere 655

5.5.1 Development of the Standard Atmosphere Model 656

5.5.2 Temperature, Pressure, and Density Ratios 661

5.6 Air Data System Measurements 663

5.6.1 The Pitot-Static System 664

5.6.2 Measurement of Altitude 665

5.6.3 Measurement of Airspeed 667

5.6.4 Types of Airspeed 672

5.6.5 Pitot-Static System Errors 678

5.6.6 Other Air Data Measurements 681

5.6.7 FTT: Altitude and Airspeed Calibration 684

5.7 The Equations of Motion for Unaccelerated Flight 690

5.8 Level Flight Performance 692

5.8.1 Thrust Required in Level, Unaccelerated Flight 693

5.8.2 Velocity and Lift Coefficient for Minimum Thrust Required 697

5.8.3 Thrust Available and Maximum Velocity 698

5.8.4 Power Required and Power Available 701

5.8.5 Velocity and Lift Coefficient for Minimum Power Required 705

5.8.6 Range and Endurance 707

5.8.7 FTT: Cruise Performance 712

5.9 Climb Performance 722

5.9.1 Maximum Angle and Maximum Rate of Climb 722

5.9.2 Time to Climb 725

5.9.3 FTT: Climb Performance 727

5.10 Glide Performance 731

5.11 The Polar Diagram 733

5.12 Energy Concepts 735

5.12.1 FTT: Specific Excess Power 745

5.13 Turn Performance 748

5.13.1 The Level Turn 748

5.13.2 Turns in the Vertical Plane 758

5.13.3 Turn Performance and the V–n Diagram 762

5.13.4 FTT: Turn Performance 763

5.14 Takeoff and Landing Performance 766

5.14.1 Takeoff Distance 771

5.14.2 Landing Distance 772

5.14.3 Solution 773

5.14.4 FTT: Takeoff Performance 774

References 778

Problems 779

6 Stability and Control 782

6.1 Introduction 783

6.2 Aircraft Stability 784

6.2.1 Static Stability 785

6.2.2 Dynamic Stability 785

6.3 Aircraft Control 787

6.3.1 Flight Controls 787

6.3.2 Stick-Fixed and Stick-Free Stability 788

6.4 Aircraft Body Axes, Sign Conventions, and Nomenclature 789

6.5 Longitudinal Static Stability 793

6.5.1 The Pitching Moment Curve 793

6.5.2 Configurations with Longitudinal Static Stability and Balance 797

6.5.3 Contributions of Aircraft Components to the Pitching Moment 801

6.5.4 Neutral Point and Static Margin 814

6.6 Longitudinal Control 817

6.6.1 Elevator Effectiveness and Control Power 818

6.6.2 Calculation of New Trim Conditions Due to Elevator Deflection 823

6.6.3 Elevator Hinge Moment 825

6.6.4 Stick-Free Longitudinal Static Stability 827

6.6.5 Longitudinal Control Forces 828

6.6.6 FTT: Longitudinal Static Stability 831

6.7 Lateral-Directional Static Stability and Control 837

6.7.1 Directional Static Stability 838

6.7.2 Directional Control 843

6.7.3 Lateral Static Stability 845

6.7.4 Roll Control 849

6.7.5 FTT: Lateral-Directional Static Stability 851

6.8 Summary of Static Stability and Control Derivatives 856

6.9 Dynamic Stability 857

6.9.1 Long Period or Phugoid 858

6.9.2 Short Period 861

6.9.3 Dutch Roll 862

6.9.4 Spiral Mode 864

6.9.5 Roll Mode 865

6.9.6 FTT: Longitudinal Dynamic Stability 866

6.10 Handling Qualities 872

6.10.1 FTT: Variable-Stability Aircraft 873

6.11 FTT: First Flight 876

References 880

Problems 880

Appendix A Constants 882

A.1 Miscellaneous Constants 882

A.2 Properties of Air at Standard Sea Level Conditions 882

Appendix B Conversions 883

B.1 Unit Conversions 883

B.2 Temperature Unit Conversions 884

Appendix C Properties of the 1976 US Standard Atmosphere 885

C.1 English Units 885

C.2 SI Units 887

Index 891