Fundamentals of Modern Unsteady Aerodynamics

by ïlgen Gïlïat

Overview

In this book, the author introduces the concept of unsteady aerodynamics and its underlying principles. He provides the readers with a comprehensive review of the fundamental physics of free and forced unsteadiness, the terminology and basic equations of aerodynamics ranging from incompressible flow to hypersonics. The book also covers modern topics related to the developments made in recent years, especially in relation to wing flapping for propulsion. The book is written for graduate and senior year undergraduate students in aerodynamics and also serves as a reference for experienced researchers. Each chapter includes ample examples, questions, problems and relevant references. The treatment of these modern topics has been completely revised end expanded for the new edition. It now includes new numerical examples, a section on the ground effect, and state-space representation.

Product Details

ISBN-13:	9789811011504
Publisher:	Springer Nature Singapore
Publication date:	08/23/2016
Edition description:	Softcover reprint of the original 2nd ed. 2016
Pages:	395
Product dimensions:	6.10(w) x 9.25(h) x (d)

About the Author

Dr. Ülgen GÜLÇAT is Emeritus Professor at the Faculty of Aeronautics and Astronautics of Istanbul Technical University (ITU).

He is expert in Computational Fluid Dynamics and studies the interaction of fluids with airfoils.

Table of Contents

1 Introduction 1

1.1 Definitions 2

1.1.1 Aerodynamics 2

1.1.2 Aerodynamic Coefficients 2

1.1.3 Center of Pressure (x_cp) 2

1.1.4 Aerodynamic Center (x_ac) 3

1.1.5 Steady Aerodynamics 3

1.1.6 Unsteady Aerodynamics 3

1.1.7 Compressible Aerodynamics 3

1.1.8 Vortex Aerodynamics 3

1.2 Generation of Life 4

1.3 Unsteady Lifting Force Coefficient 5

1.4 Steady Aerodynamics of Thin Wings 7

1.5 Unsteady Aerodynamics of Slender Wings 8

1.6 Compressible Steady Aerodynamics 8

1.7 Compressible Unsteady Aerodynamics 12

1.8 Slender Body Aerodynamics 12

1.9 Hypersonic Aerodynamics 13

1.10 The Piston Theory 15

1.11 Modern Topics 16

1.12 Questions and Problems 20

References 21

2 Fundamental Equations 23

2.1 Potential Flow 23

2.1.1 Equation of Motion 23

2.1.2 Boundary Conditions 27

2.1.3 Linearization 28

2.1.4 Acceleration Potential 33

2.1.5 Moving Coordinate System 35

2.2 Real Gas Flow 36

2.2.1 System and Control Volume Approaches 37

2.2.2 Global Continuity and the Continuity of the Species 37

2.2.3 Momentum Equation 39

2.2.4 Energy Equation 41

2.2.5 Equation of Motion in General Coordinates 42

2.2.6 Navier-Stokes Equations 44

2.2.7 Thin Shear Layer Navier-Stokes Equations 47

2.2.8 Parabolized Navier-Stokes Equations 49

2.2.9 Boundary Layer Equations 50

2.2.10 Incompressible Flow Navier-Stokes Equations 51

2.2.11 Aerodynamic Forces and Moments 52

2.2.12 Turbulence Modeling 54

2.2.13 Initial and Boundary Conditions 55

2.3 Questions and Problems 56

References 57

3 Incompressible Flow About an Airfoil 59

3.1 Impulsive Motion 59

3.2 Steady Flow 62

3.3 Unsteady Flow 67

3.4 Simple Harmonic Motion 74

3.5 Loewy's Problem: Returning Wake Problem 81

3.6 Arbitrary Motion 82

3.7 Arbitrary Motion and Wagner Function 82

3.8 Gust Problem, Küssner Function 87

3.9 Questions and Problems 92

References 94

4 Incompressible Flow About Thin Wings 95

4.1 Physical Model 95

4.2 Steady Flow 99

4.2.1 Lifting Line Theory 101

4.2.2 Weissinger's L-Method 105

4.2.3 Low Aspect Ratio Wings 107

4.3 Unsteady Flow 111

4.3.1 Reissner's Approach 113

4.3.2 Numerical Solution 116

4.4 Arbitrary Motion of a Thin Wing 119

4.5 Effect of Sweep Angle 120

4.6 Low Aspect Ratio Wing 121

4.7 Questions and Problems 123

References 127

5 Subsonic and Supersonic Flows 129

5.1 Subsonic Flow 131

5.2 Subsonic Flow about a Thin Wing 135

5.3 Subsonic Flow Past an Airfoil 137

5.4 Kernel Function Method for Subsonic Flows 139

5.5 Doublet-Lattice Method 142

5.6 Arbitrary Motion of a Profile in Subsonic Flow 144

5.7 Supersonic Flow 146

5.8 Unsteady Supersonic Flow 147

5.9 Supersonic Flow About a Profile 152

5.10 Supersonic Flow About Thin Wings 154

5.11 Mach Box Method 157

5.12 Supersonic Kernel Method 160

5.13 Arbitrary Motion of a Profile in Supersonic Flow 161

5.14 Slender Body Theory 162

5.15 Munk's Airship Theory 163

5.16 Questions and Problems 165

References 168

6 Transonic flow 171

6.1 Two Dimensional Transonic Flow, Local Linearization 171

6.2 Unsteady Transonic Flow, Supersonic Approach 176

6.3 Steady Transonic Flow, Non Linear Approach 177

6.4 Unsteady Transonic Flow: General Approach 180

6.5 Transonic Flow around a Finite Wing 184

6.6 Unsteady Transonic Flow Past Finite Wings 187

6.7 Wing-Fuselage Interactions at Transonic Regimes 189

6.8 Problems and Questions 190

References 191

7 Hypersonic Flow 193

7.1 Newton's Impact Theory 194

7.2 Improved Newton's Theory 195

7.3 Unsteady Newtonian Flow 198

7.4 The Piston Analogy 200

7.5 Improved Piston Theory: M²τ² = O(1) 203

7.6 Inviscid Hypersonic Flow: Numerical Solutions 205

7.7 Viscous Hypersonic Flow and Aerodynamic Heating 213

7.8 High Temperature Effects in Hypersonic Flow 220

7.9 Hypersonic Viscous Flow: Numerical Solutions 231

7.10 Hypersonic Plane: Waverider 236

7.11 Problems and Questions 239

References 242

8 Modern Subjects 245

8.1 Static Stall 247

8.2 Dynamic Stall 251

8.3 The Vortex Lift (Polhamus Theory) 258

8.4 Wing Rock 264

8.5 Flapping Wing Theory 274

8.6 Flexible Airfoil Flapping 289

8.7 Finite Wing Flapping 297

8.8 Problems and Questions 299

References 304

9 Aerodynamics: The Outlook for the Future 307

References 311

Appendices 313

Index 337

Editorial Reviews

From the reviews:

“This monograph, giving the progress in unsteady aerodynamics during about a century, is written as a graduate textbook. An additional aim is to provide the practicing engineers with the knowledge of the most recent developments in unsteady aerodynamics. … the author presents a three-dimensional analysis of swept wings with extra lift created by leading edge separation. Ten appendices supplement the formulae used in the basic text.” (Boris V. Loginov, Zentralblatt MATH, Vol. 1216, 2011)

From the Publisher