 | Reuss S. A grid-adaptive algebraic hybrid RANS/LES method: Diss. ... Dt. rer. nat. / Deutsches Zentrum für Luft- und Raumfahrt, Institut für Aerodynamik und Strömungstechnik, Göttingen. - Köln: DLR, 2016. - v, 170 S.: Ill. - (Forschungsbericht; 2016-31). - ISSN 1434-8454
Шифр: (Pr 1120/2016-31) 02
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Introduction .................................................... 1
Overview over Publications ...................................... 3
1 Turbulence: physical background and modeling ................. 7
1.1 Compressible Navier-Stokes equations .................... 7
1.2 Description of turbulence ............................... 9
1.3 Numerical simulation of turbulent flows ................ 10
1.3.1 Statistical turbulence modeling - RANS .......... 11
1.3.2 Large-eddy simulation - LES ..................... 13
1.3.3 Hybrid RANS/LES modeling ........................ 15
2 Numerical method: DLR-TAU ................................... 21
2.1 Discretization of the computational domain ............. 21
2.2 Discretization of the governing equations .............. 22
2.3 Optimization of the numerical scheme for scale-
resolving simulations .................................. 25
2.4 Convergence criteria and averaging ..................... 27
2.5 Chimera method and deformation tool .................... 28
3 A grid-adaptive algebraic hybrid RANS/LES model ............. 31
3.1 Motivation ............................................. 31
3.2 Grid adaptation ........................................ 34
3.2.1 Span-wise grid adaption ......................... 34
3.2.2 Grid-resolution sensors ......................... 35
3.3 Algebraic Delayed DES .................................. 37
3.3.1 Parallel evaluation of wall-normal line data .... 38
3.3.2 Algebraic boundary-layer sensors ................ 38
3.3.3 Improved LES filter width in the ADDES .......... 42
3.3.4 Synthetic turbulence at the RANS-to-LES
interface ....................................... 43
3.3.5 Sponge layer at the LES-to-RANS interface ....... 45
4 Application of the grid-adaptive algebraic hybrid RANS/LES
model ....................................................... 47
4.1 Precursor simulations of a three-element airfoil ....... 49
4.2 Turbulent channel flow ................................. 51
4.3 Backward-facing step flow .............................. 55
4.4 Wall-mounted hump flow ................................. 58
4.5 Two-element airfoil with undisturbed onflow ............ 60
4.6 Transport of a lateral vortex .......................... 68
4.7 Two-element airfoil with vortex interaction ............ 69
Conclusion .................................................. 75
References .................................................. 77
Appendix - Publications
[A| Chimera technique for transporting disturbances ............ 85
[B| Hybrid RANS/LES simulations of a three-element airfoil .... 105
[C] Investigation of the Resolution Requirements for
a Hybrid RANS/LES Simulation of a Multi-Element Airfoil ... 117
|D] Assessment of Local LES-Resolution Sensors for Hybrid
RANS/LES Simulations ...................................... 133
[E| Numerical investigation of the DLR F15 two-element
airfoil using a Reynolds stress model ..................... 145
[F] Hybrid RANS/LES Study of the Development of an Airfoil-
Generated Vortex .......................................... 157
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