Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Techniques for deriving explicit algebraic Reynolds stress models based on incomplete sets of basis tensors and predictions of fully developed rotating pipe flow
KTH, School of Engineering Sciences (SCI), Mechanics.
KTH, School of Engineering Sciences (SCI), Mechanics.ORCID iD: 0000-0001-8692-0956
KTH, School of Engineering Sciences (SCI), Mechanics.ORCID iD: 0000-0002-2711-4687
2005 (English)In: Physics of fluids, ISSN 1070-6631, Vol. 17, no 11, 115103- p.Article in journal (Refereed) Published
Abstract [en]

Different techniques for deriving explicit algebraic Reynolds stress models (EARSMs) using incomplete sets of basis tensors are discussed. The first is the Galerkin method which has been used by several authors. The second alternative technique, proposed here, is based on the least-squares method. The idea behind the latter method is to minimize the error induced in the implicit relation, i.e., the algebraic Reynolds stress model (ARSM) equation, due to the use of incomplete sets of basis tensors. It is argued that since the system matrix of the ARSM equation is not symmetric and positive definite, the Galerkin method does not give EARSMs that are optimal in the strict classical sense. The possible singular behavior depending on the choice of the basis tensors has also been investigated. It is demonstrated that many of the EARSMs based on incomplete tensor bases, expressed in general three-dimensional mean flows, have singularity problems in some flows, such as general two-dimensional (2D) mean flows or more specifically, strain- and/or rotation-free 2D mean flows. The different EARSMs emanating from the two derivation methods are investigated by computing fully developed rotating pipe flow. The results indicate that the EARSMs derived with the least-squares method capture the behavior of the complete EARSMs significantly better than those derived with the Galerkin method. Furthermore, by using mean flow data from the complete EARSMs to evaluate the square error of the incomplete EARSMs it is demonstrated that the least-squares based EARSMs have square errors significantly smaller than the Galerkin EARSMs, very close to minimum.

Place, publisher, year, edition, pages
2005. Vol. 17, no 11, 115103- p.
Keyword [en]
Complex Turbulent Flows; Viscosity
National Category
Fluid Mechanics and Acoustics
Identifiers
URN: urn:nbn:se:kth:diva-5408DOI: 10.1063/1.2131921ISI: 000233603000022Scopus ID: 2-s2.0-30044441293OAI: oai:DiVA.org:kth-5408DiVA: diva2:9768
Note
QC 20100824Available from: 2006-03-08 Created: 2006-03-08 Last updated: 2010-12-06Bibliographically approved
In thesis
1. Modelling and simulation of turbulence subject to system rotation
Open this publication in new window or tab >>Modelling and simulation of turbulence subject to system rotation
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Simulation and modelling of turbulent flows under influence of streamline curvature and system rotation have been considered. Direct numerical simulations have been performed for fully developed rotating turbulent channel flow using a pseudo-spectral code. The rotation numbers considered are larger than unity. For the range of rotation numbers studied, an increase in rotation number has a damping effect on the turbulence. DNS-data obtained from previous simulations are used to perform a priori tests of different pressure-strain and dissipation rate models. Furthermore, the ideal behaviour of the coefficients of different model formulations is investigated. The main part of the modelling is focused on explicit algebraic Reynolds stress models (EARSMs). An EARSM based on a pressure strain rate model including terms that are tensorially nonlinear in the mean velocity gradients is proposed. The new model is tested for a number of flows including a high-lift aeronautics application. The linear extensions are demonstrated to have a significant effect on the predictions. Representation techniques for EARSMs based on incomplete sets of basis tensors are also considered. It is shown that a least-squares approach is favourable compared to the Galerkin method. The corresponding optimality aspects are considered and it is deduced that Galerkin based EARSMs are not optimal in a more strict sense. EARSMs derived with the least-squares method are, on the other hand, optimal in the sense that the error of the underlying implicit relation is minimized. It is further demonstrated that the predictions of the least-squares EARSMs are in significantly better agreement with the corresponding complete EARSMs when tested for fully developed rotating turbulent pipe flow.

Place, publisher, year, edition, pages
Stockholm: KTH, 2006. viii, 34 p.
Series
Trita-MEK, ISSN 0348-467X ; 2006:04
Keyword
Direct numerical simulations, least-squares method, turbulence model, nonlinear modelling, system rotation, streamline curvature, high-lift aerodynamics
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:kth:diva-3865 (URN)
Public defence
2006-03-17, Sal F2, Lindstedtsvägen 26, Stockholm, 10:15
Opponent
Supervisors
Note
QC 20100825Available from: 2006-03-08 Created: 2006-03-08 Last updated: 2010-08-25Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Wallin, StefanJohansson, Arne V.

Search in DiVA

By author/editor
Grundestam, OlofWallin, StefanJohansson, Arne V.
By organisation
Mechanics
Fluid Mechanics and Acoustics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 71 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf