Advanced Aircraft Design

Foreword xv Series Preface xix Preface xxi Acknowledgements xxv 1 Design of theWell-Tempered Aircraft 1 1.1 How Aircraft Design Developed 1 1.2 Concept Finding 6 1.3 Product Development 8 1.4 Baseline Design in a Nutshell 13 1.5 Automated Design Synthesis 19 1.6 Technology Assessment 22 1.7 Structure of the Optimization Problem 25 Bibliography 27 2 Early Conceptual Design 31 2.1 Scenario and Requirements 31 2.2 Weight Terminology and Prediction 36 2.3 The Unity Equation 41 2.4 Range Parameter 46 2.5 Environmental Issues 51 Bibliography 56 3 Propulsion and Engine Technology 59 3.1 Propulsion Leading the Way 59 3.2 Basic Concepts of Jet Propulsion 60 3.3 Turboprop Engines 67 3.4 Turbofan Engine Layout 70 3.5 Power Plant Selection 74 4 Aerodynamic Drag and Its Reduction 81 4.1 Basic Concepts 81 4.2 Decomposition Schemes and Terminology 84 4.3 Subsonic Parasite and Induced Drag 87 4.4 Drag Polar Representations 95 4.5 Drag Prediction 99 4.6 Viscous Drag Reduction 106 4.7 Induced Drag Reduction 114 Bibliography 115 5 From Tube and Wing to Flying Wing 121 5.1 The Case for Flying Wings 121 5.2 Allocation of Useful Volume 127 5.3 Survey of Aerodynamic Efficiency 134 5.4 Survey of the Parameter ML/D 138 5.5 Integrated Configurations Compared 140 5.6 Flying Wing Design 149 Bibliography 152 6 Clean Sheet Design 157 6.1 Dominant and Radical Configurations 157 6.2 Morphology of Shapes 159 6.3 Wing and Tail Configurations 165 6.4 Aircraft Featuring a Foreplane 169 6.5 Non-Planar Lifting Systems 173 6.6 Joined Wing Aircraft 177 6.7 Twin-Fuselage Aircraft 182 6.8 Hydrogen-Fuelled Commercial Transports 186 6.9 Promising Concepts 189 Bibliography 190 7 Aircraft Design Optimization 197 7.1 The Perfect Design: An Illusion? 197 7.2 Elements of Optimization 198 7.3 Analytical or Numerical Optimization? 206 7.4 Large Optimization Problems 213 7.5 Practical Optimization in Conceptual Design 219 Bibliography 223 8 Theory of Optimum Weight 229 8.1 Weight Engineering: Core of Aircraft Design 229 8.2 Design Sensitivity 232 8.3 Jet Transport Empty Weight 234 8.4 Design Sensitivity of Airframe Drag 239 8.5 Thrust, Power Plant and Fuel Weight 243 8.6 Take-Off Weight, Thrust and Fuel Efficiency 249 8.7 Summary and Reflection 254 Bibliography 257 9 Matching Engines and Airframe 261 9.1 Requirements and Constraints 261 9.2 Cruise-Sized Engines 262 9.3 Low Speed Requirements 265 9.4 Schematic Take-Off Analysis 267 9.5 Approach and Landing 273 9.6 Engine Selection and Installation 275 Bibliography 278 10 Elements of Aerodynamic Wing Design 281 10.1 Introduction 281 10.2 Planform Geometry 283 10.3 Design Sensitivity Information 286 10.4 Subsonic Aircraft Wing 291 10.5 Constrained Optima 295 10.6 Transonic Aircraft Wing 298 10.7 Lift Coefficient and Aspect Ratio 304 10.8 Detailed Design 309 10.9 High Lift Devices 313 Bibliography 315 11 The Wing Structure and ItsWeight 319 11.1 Introduction 319 11.2 Methodology 321 11.3 Basic Wing Box 326 11.4 Inertia Relief and Design Loads 335 11.5 Non-Ideal Weight 338 11.6 Secondary Structures and Miscellaneous Items 344 11.7 Stress Levels in Aluminium Alloys 349 11.8 Refinements 352 11.9 Application 357 Bibliography 361 12 Unified Cruise Performance 363 12.1 Introduction 363 12.2 Maximum Aerodynamic Efficiency 366 12.3 The Parameter ML/D 371 12.4 The Range Parameter 374 12.5 Range in Cruising Flight 379 12.6 Cruise Procedures and Mission Fuel 382 12.7 Reflection 388 Bibliography 390 A Volumes, Surface and Wetted Areas 393 A.1 Wing 393 A.2 Fuselage 394 A.3 Tail Surfaces 395 A.4 Engine Nacelles and Pylons 395 A.5 Airframe Wetted Area 395 Bibliography 396 B International Standard Atmosphere 397 C Abbreviations 399 Index 403