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
Large-Eddy Simulation of Turbulent Flow in a Plane Asymmetric Diffuser by the Spectral-Element Method
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.ORCID iD: 0000-0001-9627-5903
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.ORCID iD: 0000-0001-7864-3071
2010 (English)In: Direct and Large-Eddy Simulation VII: Proceedings of the Seventh International ERCOFTAC Workshop on Direct and Large-Eddy Simulation, held at the University of Trieste, September 8-10, 2008 / [ed] Vincenzo Armenio, Bernard Geurts; Jochen Fröhlich, Springer , 2010, 1, 193-199 p.Chapter in book (Other academic)
Abstract [en]

LES and no-model LES (coarse-grid DNS) have been performed of turbulent flow in a plane asymmetric diffuser by the Spectral-Element Method (SEM). Mean profile and turbulent stresses compare well to LES results from Herbst e, however the SEM generally predicts a later (i.e. further downstream) separation. It can be concluded that the use of a high-order method is advantageous for flows featuring pressure-induced separation.

Place, publisher, year, edition, pages
Springer , 2010, 1. 193-199 p.
Series
ERCOFTAC Series, ISSN 1382-4309 ; Vol 13, Part 2
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-25932DOI: 10.1007/978-90-481-3652-0_29ISI: 000306194300029ISBN: 978-90-481-3651-3 (print)OAI: oai:DiVA.org:kth-25932DiVA: diva2:360908
Note

QC 20101105

Available from: 2010-11-05 Created: 2010-11-05 Last updated: 2013-05-06Bibliographically approved
In thesis
1. Spectral-element simulations of separated turbulent internal flows
Open this publication in new window or tab >>Spectral-element simulations of separated turbulent internal flows
2009 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Stockholm: US-AB, 2009. vii, 32 p.
Series
Trita-MEK, ISSN 0348-467X ; 2009:13
Keyword
spectral element method, direct numerical simulations (DNS), turbulence, dealiasing, three-dimensional separation, massively parallel simulations
Identifiers
urn:nbn:se:kth:diva-11643 (URN)978-91-7415-506-8 (ISBN)
Presentation
2009-12-15, E3, Osquars Backe 14, Stockholm, 10:15 (English)
Opponent
Supervisors
Note
QC 20101105Available from: 2009-11-27 Created: 2009-11-27 Last updated: 2010-11-05Bibliographically approved
2. Spectral-element simulations of turbulent wall-bounded flows including transition and separation
Open this publication in new window or tab >>Spectral-element simulations of turbulent wall-bounded flows including transition and separation
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. Large-eddy simulation (LES) is further performed of a plane asymmetric diffuser flow with an opening angle of 8.5 degrees, featuring turbulent flow separation. Good agreement with numerical studies of Herbst (2007) is obtained, and it is concluded that the use of a high-order method is advantageous for flows featuring pressure-induced separation. Moreover, it is shown, both a priori on simpler model problems and a posteriori using the full Navier--Stokes equations, that the numerical instability associated with SEM at high Reynolds numbers is cured either by employing over-integration (dealiasing) or a filter-based stabilisation, thus rendering simulations of moderate to high Reynolds number flows possible.

The second part of the thesis is devoted to the first direct numerical simulation (DNS) of a truly three-dimensional, turbulent and separated diffuser flow at Re = 10 000 (based on bulk velocity and inflow-duct height), experimentally investigated by Cherry et al. (2008). The massively parallel capabilities of the spectral-element method are exploited by running the simulations on up to 32 768 processors. Very good agreement with experimental mean flow data is obtained and it is thus shown that well-resolved simulations of complex turbulent flows with high accuracy are possible at realistic Reynolds numberseven in complicated geometries. An explanation for the discovered asymmetry of the mean separated flow is provided and itis demonstrated that a large-scale quasi-periodic motion is present in the diffuser.

In addition, a new diagnostic measure, based on the maximum vorticity stretching component in every spatial point, is designed and tested in a number of turbulent and transitional flows. Finally, Koopman mode decomposition is performed of a minimal channel flow and compared to classical proper orthogonal decomposition (POD).

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2011. ix, 81 p.
Series
Trita-MEK, ISSN 0348-467X ; 2011:15
Keyword
spectral-element method, direct numerical simulation (DNS), large-eddy simulation (LES), turbulence, transition, over-integration, three-dimensional separation, massively parallel simulations, proper orthogonal decomposition (POD), Koopman modes, vorticity stretching, coherence
National Category
Engineering and Technology
Research subject
SRA - E-Science (SeRC)
Identifiers
urn:nbn:se:kth:diva-50294 (URN)978-91-7501-178-3 (ISBN)
Public defence
2011-12-16, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:15 (English)
Opponent
Supervisors
Funder
Swedish Research CouncilSwedish e‐Science Research Center
Note
QC 20111206Available from: 2011-12-06 Created: 2011-12-04 Last updated: 2012-05-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Schlatter, PhilippHenningson, Dan S.

Search in DiVA

By author/editor
Ohlsson, JohanSchlatter, PhilippHenningson, Dan S.
By organisation
MechanicsLinné Flow Center, FLOW
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 125 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