Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer

Handle URI:
http://hdl.handle.net/10754/621642
Title:
Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer
Authors:
Cheng, W.; Pullin, D. I.; Samtaney, Ravi ( 0000-0002-4702-6473 )
Abstract:
© 2015 Cambridge University Press. We present large-eddy simulations (LES) of separation and reattachment of a flat-plate turbulent boundary-layer flow. Instead of resolving the near wall region, we develop a two-dimensional virtual wall model which can calculate the time- and space-dependent skin-friction vector field at the wall, at the resolved scale. By combining the virtual-wall model with the stretched-vortex subgrid-scale (SGS) model, we construct a self-consistent framework for the LES of separating and reattaching turbulent wall-bounded flows at large Reynolds numbers. The present LES methodology is applied to two different experimental flows designed to produce separation/reattachment of a flat-plate turbulent boundary layer at medium Reynolds number Reθ based on the momentum boundary-layer thickness θ. Comparison with data from the first case at demonstrates the present capability for accurate calculation of the variation, with the streamwise co-ordinate up to separation, of the skin friction coefficient, Reθ, the boundary-layer shape factor and a non-dimensional pressure-gradient parameter. Additionally the main large-scale features of the separation bubble, including the mean streamwise velocity profiles, show good agreement with experiment. At the larger Reθ = 11000 of the second case, the LES provides good postdiction of the measured skin-friction variation along the whole streamwise extent of the experiment, consisting of a very strong adverse pressure gradient leading to separation within the separation bubble itself, and in the recovering or reattachment region of strongly-favourable pressure gradient. Overall, the present two-dimensional wall model used in LES appears to be capable of capturing the quantitative features of a separation-reattachment turbulent boundary-layer flow at low to moderately large Reynolds numbers.
KAUST Department:
Mechanical Engineering Program; Physical Sciences and Engineering (PSE) Division
Citation:
Cheng W, Pullin DI, Samtaney R (2015) Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer. Journal of Fluid Mechanics 785: 78–108. Available: http://dx.doi.org/10.1017/jfm.2015.604.
Publisher:
Cambridge University Press (CUP)
Journal:
Journal of Fluid Mechanics
Issue Date:
11-Nov-2015
DOI:
10.1017/jfm.2015.604
Type:
Article
ISSN:
0022-1120; 1469-7645
Sponsors:
W.C. and R.S. were supported by the KAUST Office of Competitive Research Funds (OCRF) under Award No. URF/1/1394-01. D.I.P. was partially supported under KAUST OCRF Award No. URF/1/1394-01 and partially by NSF award CBET 1235605.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorCheng, W.en
dc.contributor.authorPullin, D. I.en
dc.contributor.authorSamtaney, Ravien
dc.date.accessioned2016-11-03T13:21:40Z-
dc.date.available2016-11-03T13:21:40Z-
dc.date.issued2015-11-11en
dc.identifier.citationCheng W, Pullin DI, Samtaney R (2015) Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer. Journal of Fluid Mechanics 785: 78–108. Available: http://dx.doi.org/10.1017/jfm.2015.604.en
dc.identifier.issn0022-1120en
dc.identifier.issn1469-7645en
dc.identifier.doi10.1017/jfm.2015.604en
dc.identifier.urihttp://hdl.handle.net/10754/621642-
dc.description.abstract© 2015 Cambridge University Press. We present large-eddy simulations (LES) of separation and reattachment of a flat-plate turbulent boundary-layer flow. Instead of resolving the near wall region, we develop a two-dimensional virtual wall model which can calculate the time- and space-dependent skin-friction vector field at the wall, at the resolved scale. By combining the virtual-wall model with the stretched-vortex subgrid-scale (SGS) model, we construct a self-consistent framework for the LES of separating and reattaching turbulent wall-bounded flows at large Reynolds numbers. The present LES methodology is applied to two different experimental flows designed to produce separation/reattachment of a flat-plate turbulent boundary layer at medium Reynolds number Reθ based on the momentum boundary-layer thickness θ. Comparison with data from the first case at demonstrates the present capability for accurate calculation of the variation, with the streamwise co-ordinate up to separation, of the skin friction coefficient, Reθ, the boundary-layer shape factor and a non-dimensional pressure-gradient parameter. Additionally the main large-scale features of the separation bubble, including the mean streamwise velocity profiles, show good agreement with experiment. At the larger Reθ = 11000 of the second case, the LES provides good postdiction of the measured skin-friction variation along the whole streamwise extent of the experiment, consisting of a very strong adverse pressure gradient leading to separation within the separation bubble itself, and in the recovering or reattachment region of strongly-favourable pressure gradient. Overall, the present two-dimensional wall model used in LES appears to be capable of capturing the quantitative features of a separation-reattachment turbulent boundary-layer flow at low to moderately large Reynolds numbers.en
dc.description.sponsorshipW.C. and R.S. were supported by the KAUST Office of Competitive Research Funds (OCRF) under Award No. URF/1/1394-01. D.I.P. was partially supported under KAUST OCRF Award No. URF/1/1394-01 and partially by NSF award CBET 1235605.en
dc.publisherCambridge University Press (CUP)en
dc.subjectturbulence modellingen
dc.subjectturbulent boundary layersen
dc.subjectturbulent flowsen
dc.titleLarge-eddy simulation of separation and reattachment of a flat plate turbulent boundary layeren
dc.typeArticleen
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalJournal of Fluid Mechanicsen
dc.contributor.institutionGraduate Aerospace Laboratories, California Institute of TechnologyCA, United Statesen
kaust.authorSamtaney, Ravien
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