 | Stephan A. Wake vortices of landing aircraft: Diss. / Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen. - Köln: DLR, 2014. - xxii, 148 p.: ill. - (Forschungsbericht; 2014-10). - Bibliogr.: p. 137-147. - Пер. загл.: Вихревой след самолета при посадке - ISSN 1434-8454
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Abstract ....................................................... vi
Zusammenfassung ................................................ ix
1 Introduction ............................................... 1
1.1 Motivation ................................................. 1
1.2 Aims of the Thesis ......................................... 2
1.3 State-of-the-art - Recent Developments ..................... 7
1.4 Overview over the Thesis .................................. 10
2 Methods ................................................... 13
2.1 Wake-Vortex Principles .................................... 13
2.1.1 Wake-vortex and lift generation of an aircraft ..... 13
2.1.2 Wing in ground effect .............................. 16
2.1.3 Phases of wake-vortex evolution .................... 17
2.1.4 Landing phases ..................................... 19
2.1.5 Flight test data ................................... 21
2.1.6 Vortex models and parameters ....................... 23
2.2 Ambient Turbulence Field .................................. 28
2.2.1 Ambient wind ....................................... 28
2.2.2 Strut wake turbulence .............................. 30
2.3 LES Code .................................................. 32
2.3.1 Governing equations ................................ 33
2.3.2 Lagrangian dynamic subgrid-scale model ............. 34
2.3.3 Fourth-order finite volume compact scheme .......... 36
2.3.4 Split-interface algorithm .......................... 37
2.3.5 Velocity-pressure iteration method on a multi
grid ............................................... 37
2.3.6 Third-order Runge-Kutta ............................ 38
2.3.7 Obstacle modeling .................................. 39
2.4 LES of Boundary Layer Flow ................................ 39
2.4.1 Resolution requirements and computational
complexity ......................................... 40
2.4.2 Wall model for the ground surface .................. 41
2.5 RANS/LES Coupling ......................................... 42
2.5.1 Fortified solution algorithm ....................... 43
2.5.2 RANS/LES interface ................................. 44
2.5.3 Aircraft descent and touchdown ..................... 45
2.5.4 Boundary treatment ................................. 47
2.6 Turbulence Initialization ................................. 47
2.6.1 Wind initialization ................................ 47
2.6.2 Strut wake initialization .......................... 48
2.7 Wake-Vortex Initialization ................................ 50
2.7.1 Temporal LES ....................................... 50
2.7.2 Spatial LES ........................................ 51
2.7.3 RANS flow field .................................... 51
2.8 Computational Domain ...................................... 52
2.8.1 Temporal LES ....................................... 52
2.8.2 Spatial LES ........................................ 53
2.9 Post-Processing ........................................... 54
2.9.1 Vortex center tracking ............................. 54
2.9.2 Secondary vortex helix ............................. 55
3 Results ................................................... 57
3.1 Listing of Simulations .................................... 57
3.2 Flow Field of a Landing Aircraft .......................... 59
3.2.1 Complete landing ................................... 59
3.2.2 Vortex pair in ground proximity .................... 62
3.2.3 Crosswind effect ................................... 62
3.2.4 Obstacle effect .................................... 63
3.3 Wake-Vortex Evolution With Flat Ground .................... 65
3.3.1 In ground effect without turbulence, academic
case ............................................... 65
3.3.2 Wake-vortex decay mechanisms in crosswind
situation .......................................... 65
3.3.3 Trajectories and decay ............................. 69
3.3.4 The effect of a wall model in high Reynolds
number flows ....................................... 71
3.4 Obstacle Effects .......................................... 73
3.4.1 Detailed analysis of vortex dynamics with
obstacle ........................................... 73
3.4.2 Trajectories and decay ............................. 79
3.4.3 Effects of different obstacle geometries and
headwind ........................................... 80
3.5 Wing-in-Ground Effect ..................................... 84
3.6 Touchdown Effects ......................................... 86
3.6.1 Vortex divergence .................................. 86
3.6.2 End effects ........................................ 86
3.7 Wake Vortex Topology ...................................... 89
3.8 Vortex Decay and Core Radius Evolution .................... 89
3.8.1 Flat ground ........................................ 89
3.8.2 Plate line effects ................................. 91
3.8.3 Wake-vortex decay phases in ground proximity ....... 93
4 Discussion ................................................ 95
4.1 Comparison of LES with Towing Tank Experiments ............ 95
4.1.1 Experimental setup - water towing tank ............. 95
4.1.2 Numerical setup .................................... 96
4.1.3 Simulation ......................................... 96
4.1.4 Experiment ......................................... 98
4.1.5 Trajectories and decay ............................ 100
4.1.6 Propagation of end effects ........................ 104
4.1.7 Effects of several obstacles ...................... 104
4.2 Comparison with field measurement campaigns .............. 107
4.2.1 Frankfurt (WakeFRA) ............................... 108
4.2.2 Munich (WakeMUC) .................................. 108
4.3 General Remarks .......................................... 114
5 Conclusions and Outlook .................................. 115
A Appendix: Aircraft Geometry ................................ 119
B Appendix: Rough Surfaces ................................... 123
Nomenclature .................................................. 125
Abbildungsverzeichnis ......................................... 131
Tabellenverzeichnis ........................................... 135
Literaturverzeichnis .......................................... 137
Acknowledgments ............................................... 148
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