Vortex wakes of Aircrafts (eBook)

Contents 5
Abstract 8
Foreword 9
Introduction 11
Chapter 1 GENERAL 16
1.1. Atmospheric turbulence 16
1.2. Aircraft vortex wake 19
1.3. Turbulence characteristics of the vortex wake 24
1.4. Present-day methods for numerical simulation of vortex wakes behind trunk-route aircraft 25
Chapter 2 DISCRETE VORTEX METHOD 27
2.1. Problem statement 27
2.2. Fundamentals of the discrete vortex method 31
2.3. Point vortex 32
2.4. Vortex segment 33
2.5. Closed vortex frame 34
2.6. Numerical modeling of free turbulence in separated and jet flows in the framework of the discrete vortex method 35
Chapter 3 THE NEAR VORTEX WAKE BEHIND A SINGLE AIRCRAFT 47
3.1. Aircraft geometry representation 47
3.2. Vorticity panel representation 48
3.3. Peculiarities of flow simulation around trunk-route aircraft 48
3.4. The characteristics of the near vortex wake behind some aircraft 49
Chapter 4 FAR VORTEX WAKE BEHIND A TURBOJET AIRCRAFT 52
4.1. The algorithm for computation of the far vortex wake behind aircraft 52
4.2. Mathematical model of the far vortex wake 54
4.3. Check for the existence and uniqueness of the solution 55
4.4. Similarity considerations for flow in the far vortex wake 60
4.5. A universal procedure for transition to the mathematical model of the far vortex wake 63
4.6. Consideration of the state of the atmosphere 66
4.7. Verification of the method and predicted results 68
4.8. The characteristics of the vortex wake behind the Il-76 aircraft 70
4.9. The characteristics of the vortex wake behind the An-124, B-747 and A-380 aircraft 74
Chapter 5 VORTEX WAKES BEHIND PROPELLER-DRIVEN AIRCRAFT 84
5.1. Problem statement 84
5.2. The effect of propellers on the far vortex wake characteristics 85
5.3. On a rational number of vortices for modeling a propeller 89
5.4. Examples of computed far vortex wake characteristics of propeller-driven aircraft in comparison with experimental data 91
5.5. The characteristics of the vortex wake behind the An-26 aircraft 92
5.6. The characteristics of the vortex wake behind the An-12 aircraft 97
5.7. The characteristics of the vortex wake behind the C-130 aircraft 103
Chapter 6 WIND FLOW OVER ROUGH TERRAIN 111
6.1. Basic conditions 111
6.2. Problem statement 111
6.3. A solution technique. Terrain representation 112
6.4. Examples of air flow computations 112
Chapter 7 SIMULATION OF THE FAR VORTEX WAKE OF AN AIRCRAFT AT TAKEOFF AND LANDING 117
7.1. Problem statement 117
7.2. Simulation of an aircraft’s near vortex wake. Linear theory 120
7.3. An approximate computation of an aircraft’s far vortex wake 127
7.4. Generation of crossflow by vortex tubes. Turbulent boundary layer computation 128
7.5. Computation of the far vortex wake behind the B-727 aircraft with account for the effect of the boundary layer on an aerodrome’s surface. Comparison between computational results and flight test data 130
7.6. Computation of the far vortex wake of Russian–built Tu-204 and Il-96 trunk-route aircraft at landing 134
7.7. On the visualization of an aircraft’s far vortex wake near the ground 137
7.8. Conclusions and prospects 138
Chapter 8 AERODYNAMIC LOADS ON AIRCRAFT ENCOUNTERING VORTEX WAKES OF OTHER AIRCRAFT 141
8.1. Problem statement 141
8.2. A solution technique 142
8.3. Verification of the method and predicted results 143
8.4. The aerodynamic loads on aircraft in the far vortex wakes of preceding aircraft 146
8.5. Prediction of the effect of wind flow over rough terrain on the aerodynamic loads experienced by an aircraft 149
8.6. Numerical prediction of an aircraft’s dynamics in a vortex wake 156
References 161