Basic Helicopter Aerodynamics

Basic Helicopter Aerodynamics is widely appreciated as an easily accessible, rounded introduction to the first principles of the aerodynamics of helicopter flight. Simon Newman has brought this third edition completely up to date with a full new set of illustrations and imagery. An accompanying website href="http://www.wiley.com/go/seddon">www.wiley.com/go/seddon contains all the calculation files used in the book, problems, solutions, PPT slides and supporting MATLAB® code. Simon Newman addresses the unique considerations applicable to rotor UAVs and MAVs, and coverage of blade dynamics is expanded to include both flapping, lagging and ground resonance. New material is included on blade tip design, flow characteristics surrounding the rotor in forward flight, tail rotors, brown-out, blade sailing and shipborne operations. Concentrating on the well-known Sikorsky configuration of single main rotor with tail rotor, early chapters deal with the aerodynamics of the rotor in hover, vertical flight, forward flight and climb. Analysis of these motions is developed to the stage of obtaining the principal results for thrust, power and associated quantities. Later chapters turn to the characteristics of the overall helicopter, its performance, stability and control, and the important field of aerodynamic research is discussed, with some reference also to aerodynamic design practice. This introductory level treatment to the aerodynamics of helicopter flight will appeal to aircraft design engineers and undergraduate and graduate students in aircraft design, as well as practising engineers looking for an introduction to or refresher course on the subject.

Autorentext

John Seddon, Formerly of the Ministry of Defence, UK Simon Newman, University of Southampton, UK

Klappentext
Basic Helicopter Aerodynamics Third Edition Basic Helicopter Aerodynamics is widely appreciated as an easily accessible, rounded introduction to the first principles of the aerodynamics of helicopter flight. Simon Newman has brought this third edition completely up to date with a full new set of illustrations and imagery. An accompanying website www.wiley.com/go/seddon contains all the calculation files used in the book, problems, solutions, PPT slides and supporting MATLAB® code. Simon Newman addresses the unique considerations applicable to rotor UAVs and MAVs, and coverage of blade dynamics is expanded to include both flapping, lagging and ground resonance. New material is included on blade tip design, flow characteristics surrounding the rotor in forward flight, tail rotors, brown-out, blade sailing and shipborne operations. Concentrating on the well-known Sikorsky configuration of single main rotor with tail rotor, early chapters deal with the aerodynamics of the rotor in hover, vertical flight, forward flight and climb. Analysis of these motions is developed to the stage of obtaining the principal results for thrust, power and associated quantities. Later chapters turn to the characteristics of the overall helicopter, its performance, stability and control, and the important field of aerodynamic research is discussed, with some reference also to aerodynamic design practice. This introductory level treatment to the aerodynamics of helicopter flight will appeal to aircraft design engineers and undergraduate and graduate students in aircraft design, as well as practising engineers looking for an introduction to or refresher course on the subject.

Zusammenfassung
Basic Helicopter Aerodynamics is widely appreciated as an easily accessible, rounded introduction to the first principles of the aerodynamics of helicopter flight. Simon Newman has brought this third edition completely up to date with a full new set of illustrations and imagery. An accompanying website www.wiley.com/go/seddon contains all the calculation files used in the book, problems, solutions, PPT slides and supporting MATLAB® code. Simon Newman addresses the unique considerations applicable to rotor UAVs and MAVs, and coverage of blade dynamics is expanded to include both flapping, lagging and ground resonance. New material is included on blade tip design, flow characteristics surrounding the rotor in forward flight, tail rotors, brown-out, blade sailing and shipborne operations.

Concentrating on the well-known Sikorsky configuration of single main rotor with tail rotor, early chapters deal with the aerodynamics of the rotor in hover, vertical flight, forward flight and climb. Analysis of these motions is developed to the stage of obtaining the principal results for thrust, power and associated quantities. Later chapters turn to the characteristics of the overall helicopter, its performance, stability and control, and the important field of aerodynamic research is discussed, with some reference also to aerodynamic design practice.

This introductory level treatment to the aerodynamics of helicopter flight will appeal to aircraft design engineers and undergraduate and graduate students in aircraft design, as well as practising engineers looking for an introduction to or refresher course on the subject.

Inhalt

About the Authors xi

Series Preface xiii

Preface to First Edition xv

Preface to Second Edition xvii

Preface to Third Edition xix

Notation xxiii

Units xxvii

Abbreviations xxix

1 Introduction 1

1.1 Looking Back 1

1.1.1 Early Years 1

1.1.2 First World War Era 3

1.1.3 Inter-war Years 3

1.1.4 Second World War Era 6

1.1.5 Post-war Years 7

1.1.6 The Helicopter from an Engineering Viewpoint 13

1.2 Book Presentation 22

Reference 22

2 Rotor in Vertical Flight: Momentum Theory and Wake Analysis 23

2.1 Momentum Theory for Hover 23

2.2 Non-dimensionalization 25

2.3 Figure of Merit 26

2.4 Axial Flight 29

2.5 Momentum Theory for Vertical Climb 29

2.6 Modelling the Streamtube 34

2.7 Descent 37

2.8 Wind Tunnel Test Results 45

2.9 Complete Induced-Velocity Curve 49

2.9.1 Basic Envelope 49

2.9.2 Autorotation 51

2.9.3 Ideal Autorotation 52

2.10 Summary Remarks on Momentum Theory 52

2.11 Complexity of Real Wake 53

2.12 Wake Analysis Methods 55

2.13 Ground Effect 58

2.14 Brownout 60

References 61

3 Rotor in Vertical Flight: Blade Element Theory 63

3.1 Basic Method 63

3.2 Thrust Approximations 68

3.3 Non-uniform Inflow 70

3.3.1 Constant Downwash 71

3.4 Ideal Twist 71

3.5 Blade Mean Lift Coefficient 73

3.6 Power Approximations 74

3.7 Tip Loss 76

3.8 Example of Hover Characteristics 78

Reference 78

4 Rotor Mechanisms for Forward Flight 79

4.1 The Edgewise Rotor 79

4.2 Flapping Motion 85

4.3 Rotor Control 88

4.4 Equivalence of Flapping and Feathering 94

4.4.1 Blade Sailing 95

4.4.2 Lagging Motion 95

4.4.3 Coriolis Acceleration 95

4.4.4 Lag Frequency 98

4.4.5 Blade Flexibility 99

4.4.6 Ground Resonance 99

References 109

5 Rotor Aerodynamics in Forward Flight 111

5.1 Momentum Theory 111

5.2 Descending Forward Flight 115

5.3 Wake Analysis 120

5.3.1 Geometry of the Rotor Flow 120

5.4 Blade Element Theory 125

5.4.1 Factors Involved 125

5.4.2 Thrust 128

5.4.3 In-Plane H-force 130

5.4.4 Torque and Power 131

5.4.5 Flapping Coefficients 133

5.4.6 Typical Numerical Values 136

References 138

6 Aerodynamic Design 139

6.1 Introductory 139

6.2 Blade Section Design 139

6.3 Blade Tip Shapes 144

6.3.1 Rectangular 144

6.3.2 Swept 144

6.3.3 Advanced Planforms 146

6.4 Tail Rotors 148

6.4.1 Propeller Moment 151

6.4.2 Precession Yaw Agility 155

6.4.3 Calculation of Downwash 160

6.4.4 Yaw Acceleration 162

6.4.5 Example Sea King 164

6.5 Parasite Drag 165

6.6 Rear Fuselage Upsweep 168

6.7 Higher Harmonic Control 172

6.8 Aerodynamic Design Process 173

References 177

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