Flight Performance of Fixed and Rotary Wing Aircraft (eBook)

Front cover 1
Title page 4
Copyright page 5
Table of contents 6
Preface 12
Acknowledgments 16
List of Tables 18
Nomenclature: organizations 20
Nomenclature: acronyms 21
Nomenclature: main symbols 23
Nomenclature: Greek symbols 26
Nomenclature: subscripts/superscripts 27
Supplements to the text 28
Part I Fixed-Wing Aircraft Performance 30
1 Introduction 32
1.1 Physical units used 33
1.2 Performance parameters 34
1.3 Performance optimization 36
1.4 Certificate of Airworthiness 36
1.5 Upgrading of aircraft performance 37
1.6 Mission profiles 38
1.6.1 Fighter Aircraft Requirements 40
1.6.2 Supersonic Commercial Aircraft Requirements 42
Problems 42
2 The aircraft and its environment 44
2.1 General aircraft model 44
2.2 Reference systems 46
2.2.1 Angular Relationships 48
2.3 Forces on the aircraft 49
2.4 Moments of inertia 50
2.5 Flight dynamics equations 51
2.6 The International Standard Atmosphere 52
2.7 Non-standard conditions 57
Problems 59
3 Weight performance 62
3.1 The aircraft's weight 62
3.1.1 Wing Loading 67
3.2 Definition of weights 69
3.3 Weight estimation 71
3.4 Weight management 71
3.5 Range/payload diagram 73
3.6 Direct Operating Costs 75
Problems 76
4 Aerodynamic performance 78
4.1 Aerodynamic forces 78
4.2 Lift equation 80
4.3 Vortex lift 81
4.4 High-lift systems 84
4.5 Drag equation 86
4.5.1 Zero-Lift Drag 88
4.6 Glide ratio 90
4.7 Glide ratio at transonic and supersonic speed 92
4.8 Practical estimation of the drag coefficient 94
4.9 Compressibility effects 95
4.10 Transonic drag rise 96
4.11 Lift and transonic buffet 97
4.12 Aero-thermodynamic heating 98
4.13 Aerodynamic penetration and radius 100
4.14 Aircraft vortex wakes 101
4.15 Aerodynamics and performance 103
Problems 104
5 Engine performance 106
5.1 Gas turbine engines 106
5.2 Internal combustion engines 110
5.3 Engine flight envelopes 112
5.4 Power and thrust definitions 113
5.5 Generalized engine performance 115
5.6 Fuel flow 117
5.6.1 Aspects of Fuel Consumption 121
5.7 Propulsive efficiency 122
5.8 Thrust characteristics 123
5.9 Propeller characteristics 124
5.9.1 The Axial Momentum Theory 130
5.9.2 The Blade Element Method 134
Problems 137
6 Flight envelopes 140
6.1 General definitions 140
6.2 Aircraft speed range 141
6.3 Definition of speeds 142
6.4 Steady state level flight 146
6.5 Speed in level flight 146
6.6 Absolute ceiling of jet aircraft 148
6.7 Absolute ceiling of propeller aircraft 148
6.8 Optimal speeds for level flight 150
6.9 General flight envelopes 153
6.10 Limiting factors on flight envelopes 155
6.11 Dash speed of supersonic aircraft 157
6.12 Absolute ceiling of supersonic aircraft 160
6.13 Supersonic acceleration 160
6.13.1 Acceleration at Constant Altitude 161
6.13.2 Other Acceleration Profiles 163
Problems 164
7 Take-off and landing 166
7.1 Definition of terminal phases 166
7.2 Conventional take-off 168
7.3 Ground run of jet aircraft 170
7.4 Solutions of the take-off equation 172
7.5 Rotation and initial climb 177
7.6 Take-off with one engine inoperative 179
7.7 Calculation of the balanced field length 180
7.8 Ground run of propeller aircraft 182
7.9 WAT charts 183
7.10 Missed take-off 184
7.11 Final approach and landing 185
7.12 Landing run 186
7.13 Effects of the wind 190
7.14 Ground maneuvering 190
Problems 190
8 Climb and gliding 194
8.1 Governing equations 194
8.2 Rate of climb 195
8.3 Steady climb of propeller airplane 196
8.3.1 Fastest Climb of Propeller Airplane 197
8.3.2 Optimal Climb with Engine and Propeller Data 198
8.3.3 Climb at Maximum Angle of Climb 202
8.3.4 Climb Fuel of Propeller Airplane 203
8.4 Climb of jet airplane 204
8.4.1 CL for Optimal Steady Rate of Climb 205
8.4.2 Practical Calculation of Climb Fuel 207
8.5 Polar diagram for rate of climb 208
8.6 Energy methods 210
8.7 Specific excess power diagrams 212
8.8 Differential excess power plots 213
8.9 Minimum problems with energy method 215
8.9.1 Minimum Time to Climb and Steepest Climb 215
8.9.2 Minimum Fuel to Climb 216
8.9.3 Other Climb Profiles 217
8.10 Steady state gliding 219
8.10.1 Minimum Sinking Speed at Subsonic Speed 219
8.10.2 Minimum Glide Angle Versus Minimum Sinking Speed 220
8.11 General gliding flight 223
8.12 Maximum glide range with energy method 225
8.13 Minimum flight paths 227
8.13.1 Minimum Time to Climb 228
8.13.2 Solution of the Problem 229
8.14 Additional research on aircraft climb 230
Problems 231
9 Cruise performance 234
9.1 Importance of the cruise flight 234
9.2 General definitions 235
9.3 Point performance 235
9.3.1 Specific Range at Subsonic Speed 236
9.3.2 Specific Range at Supersonic Speed 239
9.3.3 Specific Endurance, Es 240
9.3.4 Figure of Merit, M (L/D) 242
9.4 The Breguet range equation 245
9.5 Subsonic cruise of jet aircraft 247
9.5.1 Cruise at Constant Altitude and Constant Mach Number 247
9.5.2 Cruise at Constant Altitude and Lift Coefficient 248
9.5.3 Cruise at Constant Mach Number and Constant CL 249
9.5.4 Comparison Between Cruise Programs 251
9.5.5 Fuel Burn for Given Range 251
9.6 Mission fuel 253
9.6.1 Fuel for Taxi and Take-off 253
9.6.2 Fuel to Climb 254
9.6.3 Additional Fuel 254
9.6.4 Reserve Fuel 255
9.6.5 Mission Fuel of Subsonic Jet Transport 256
9.7 Cruise with intermediate stop 259
9.8 Aircraft selection 261
9.9 Supersonic cruise 262
9.9.1 Cruise at Constant Altitude and Mach Number 262
9.9.2 Cruise at Constant Mach Number and CL 264
9.10 Cruise range of propeller aircraft 266
9.10.1 Cruise at Constant Altitude and Speed 266
9.11 Endurance 267
9.12 Effect of weight on cruise range 268
9.13 Effect of the wind on cruise range 268
9.14 Additional research on aircraft cruise 270
9.15 Formation flight 270
9.15.1 Range and Endurance in Formation Flight 275
Problems 277
10 Maneuver performance 280
10.1 Banked level turns 280
10.2 Banked turn at constant thrust 282
10.3 Power requirements 284
10.4 Effect of weight on turn radius 285
10.5 Maneuver envelope: n–V diagram 286
10.6 Turn rates 288
10.6.1 Corner Velocity 290
10.7 Sustainable g-loads 291
10.8 Unpowered turn 293
10.9 Soaring flight 294
10.10 Roll performance 300
10.10.1 Effects of Mach number 307
10.10.2 Dihedral Effect 310
10.11 Aircraft control under thrust asymmetry 312
10.12 Pull-up maneuver and the loop 316
10.13 Zero-gravity atmospheric flight 318
10.14 Flight path to a moving target 324
Problems 326
Part II Rotary-Wing Aircraft Performance 328
11 Rotorcraft performance 330
11.1 Fundamentals 330
11.2 Helicopter configurations 331
11.3 Mission profiles 334
11.4 Flight envelopes 335
11.5 Definitions and reference systems 336
11.5.1 Rotor Parameters 338
11.6 Non-dimensional parameters 340
11.7 Methods for performance calculations 341
Problems 342
12 Rotorcraft in vertical flight 344
12.1 Hover performance 344
12.1.1 Profile Power 347
12.1.2 Blade Element Analysis in Hover 349
12.1.3 Power Loading 351
12.2 Effect of blade twist 352
12.3 Non-dimensional hover performance 353
12.4 Vertical climb 355
12.5 Ceiling performance 357
12.6 Ground effect 360
12.7 Vertical descent 361
12.8 Hover endurance 363
Problems 364
13 Rotorcraft in forward flight 366
13.1 Asymmetry of rotor loads 366
13.2 Power requirements 367
13.2.1 Induced Power 368
13.2.2 Blade Profile Power 372
13.2.3 Compressibility Effects 373
13.2.4 Vehicle Drag 375
13.2.5 Interference Effect of the Airframe 379
13.2.6 Tail Rotor Power 380
13.3 Rotor disk angle 386
13.4 Calculation of forward flight power 388
13.5 L/D of the helicopter 390
13.6 Forward flight analysis 391
13.6.1 Effect of Gross Weight 392
13.6.2 Effect of Flight Altitude 394
13.6.3 Effect of Atmospheric Conditions 394
13.7 Propulsive efficiency 395
13.8 Climb performance 396
13.9 Performance of tandem helicopters 399
13.9.1 Assembling the Power Requirements 401
13.9.2 Tandem Helicopter: Example of Calculation 404
13.10 Single or tandem helicopter? 406
Problems 409
14 Rotorcraft maneuver 412
14.1 Limits on flight envelopes 412
14.2 Kinetic energy of the rotor 414
14.3 Autorotative index 416
14.4 Autorotative performance 418
14.4.1 Steady Autorotative Performance 418
14.4.2 Transient Autorotative Performance 424
14.4.3 Flare and Touchdown 427
14.5 Height/velocity diagram 427
14.6 The vortex ring state 429
14.7 Take-off and landing 433
14.8 Turn performance 433
14.9 Power required for turning 435
14.9.1 Unrestricted Turn 438
14.10 More on tail rotor performance 439
Problems 441
15 Rotorcraft mission analysis 442
15.1 Specific air range 442
15.2 Non-dimensional analysis of the SAR 444
15.3 Endurance and specific endurance 445
15.4 Speed for minimum power 446
15.5 Speed for maximum range 448
15.6 Fuel to climb 449
15.7 Payload/range diagram 451
15.8 Comparative payload fraction 457
15.9 Mission analysis 458
Problems 459
Part III V/STOL and Noise Performance 462
16 V/STOL performance 464
16.1 Hover characteristics 464
16.2 Jet-induced lift 466
16.2.1 Estimation of Jet-induced Fountain Lift and Suck-down 468
16.3 Lift augmentation 469
16.4 Calculation of short take-off 470
16.5 Ski jump 474
16.6 Convertiplanes or tilt rotors 477
16.7 V/STOL flight envelopes 478
Problems 478
17 Noise performance 480
17.1 Definitions of sound and noise 481
17.1.1 Doppler Effect 482
17.1.2 Sources of Noise 483
17.2 Trends in noise reduction 483
17.3 Airframe noise of fixed-wing aircraft 485
17.3.1 Airframe Noise at High Lift 487
17.3.2 Noise from Control Surfaces and Landing Gear 487
17.3.3 Airframe Noise Reduction 488
17.4 Engine noise 489
17.5 Noise certification procedure 490
17.6 Noise reduction from operations 493
17.7 Minimum noise to climb 496
17.8 Helicopter noise 498
17.8.1 Rotational Noise 500
17.8.2 Impulsive Noise 500
17.9 Helicopter noise reduction 501
17.10 Noise certification of civil helicopters 501
17.11 Sonic boom 502
Problems 507
Appendix A. Aircraft models 508
A.1 Aircraft A: subsonic commercial jet 508
A.2 Aircraft B: turboprop transport aircraft 513
A.3 Aircraft C: supersonic jet fighter 516
A.4 Aircraft D: General utility helicopter 523
A.4.1 Main Rotor 524
A.4.2 Engines 525
A.4.3 Discussion of Data 526
A.5 Aircraft E: tandem helicopter 531
A.5.1 Rotor System 531
A.5.2 Aircraft Versions 531
Appendix B. Noise data 536
Appendix C. Selected simulation programs 538
C.1 Assembling aircraft forces 538
C.2 Calculation of numerical derivatives 539
C.3 Optimal climb of fighter jet aircraft 539
C.4 Optimal climb rate of turboprop 542
C.5 Calculation of mission fuel 544
C.6 Supersonic acceleration 547
C.7 Asymmetric thrust control 550
C.8 Hover power with blade element theory 553
C.9 Forward flight power of helicopter 555
Bibliography 560
Index 582