Knopp, Tobias (2016) A new wall-law for adverse pressure gradient flows and modification of k-omega type RANS turbulence models. American Institute of Aeronautics and Astronautics. AIAA SciTech 2016 - AIAA Science and Technology Forum and Exposition, 04. - 08. Jan. 2016, San Diego, USA.
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Official URL: https://www.aiaa-scitech.org/
Abstract
We present an attempt to improve the predictive accuracy of RANS turbulence models for low-speed flow separation on airfoils and wings near stall. It is based on a proposal for a new wall-law for the mean velocity in the inner layer of a turbulent boundary layer at adverse pressure gradient. The wall-law is a composite law with a log-law in the inner part and a half-power (or sqrt-) law in the outer part of the inner layer. The wall law is calibrated using a large experimental database. The slope coefficient for log-law and sqrt-law and the wall distance for transition between them depends on the pressure gradient parameter. We describe the corresponding wall law for the turbulent viscosity and for k and omega in k-omega RANS turbulence models. We propose a modification for the k- and omega-equation such that the wall law for the inner layer is satisfied. We apply the modified SST model to a new turbulent boundary layer experiment and to airfoil flows near maximum lift at different Reynolds numbers. The modification leads to a reduction of the skin-friction coefficient in the adverse pressure gradient region and causes an upstream shift of the separation line.
Item URL in elib: | https://elib.dlr.de/100244/ | ||||||
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Document Type: | Conference or Workshop Item (Speech) | ||||||
Additional Information: | AIAA-2016- | ||||||
Title: | A new wall-law for adverse pressure gradient flows and modification of k-omega type RANS turbulence models | ||||||
Authors: |
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Date: | 2016 | ||||||
Refereed publication: | No | ||||||
Open Access: | No | ||||||
Gold Open Access: | No | ||||||
In SCOPUS: | No | ||||||
In ISI Web of Science: | No | ||||||
Page Range: | pp. 1-23 | ||||||
Publisher: | American Institute of Aeronautics and Astronautics | ||||||
Series Name: | Conference Proceedings online | ||||||
Status: | Published | ||||||
Keywords: | turbulent boundary layer, adverse pressure gradient, log-law, scaling law, k-omega RANS models | ||||||
Event Title: | AIAA SciTech 2016 - AIAA Science and Technology Forum and Exposition | ||||||
Event Location: | San Diego, USA | ||||||
Event Type: | international Conference | ||||||
Event Dates: | 04. - 08. Jan. 2016 | ||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||
HGF - Program: | Aeronautics | ||||||
HGF - Program Themes: | fixed-wing aircraft | ||||||
DLR - Research area: | Aeronautics | ||||||
DLR - Program: | L AR - Aircraft Research | ||||||
DLR - Research theme (Project): | L - Simulation and Validation (old) | ||||||
Location: | Göttingen | ||||||
Institutes and Institutions: | Institute of Aerodynamics and Flow Technology > C²A²S²E - Center for Computer Applications in AeroSpace Science and Engineering | ||||||
Deposited By: | Bachmann, Barbara | ||||||
Deposited On: | 26 Sep 2016 15:34 | ||||||
Last Modified: | 26 Sep 2016 15:34 |
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