Large-eddy simulation of flow over a cylinder with from to : a skin-friction perspective

Handle URI:
http://hdl.handle.net/10754/623860
Title:
Large-eddy simulation of flow over a cylinder with from to : a skin-friction perspective
Authors:
Cheng, Wan; Pullin, D. I.; Samtaney, Ravi ( 0000-0002-4702-6473 ) ; Zhang, W.; Gao, Wei
Abstract:
We present wall-resolved large-eddy simulations (LES) of flow over a smooth-wall circular cylinder up to , where is Reynolds number based on the cylinder diameter and the free-stream speed . The stretched-vortex subgrid-scale (SGS) model is used in the entire simulation domain. For the sub-critical regime, six cases are implemented with . Results are compared with experimental data for both the wall-pressure-coefficient distribution on the cylinder surface, which dominates the drag coefficient, and the skin-friction coefficient, which clearly correlates with the separation behaviour. In the super-critical regime, LES for three values of are carried out at different resolutions. The drag-crisis phenomenon is well captured. For lower resolution, numerical discretization fluctuations are sufficient to stimulate transition, while for higher resolution, an applied boundary-layer perturbation is found to be necessary to stimulate transition. Large-eddy simulation results at , with a mesh of , agree well with the classic experimental measurements of Achenbach (J. Fluid Mech., vol. 34, 1968, pp. 625-639) especially for the skin-friction coefficient, where a spike is produced by the laminar-turbulent transition on the top of a prior separation bubble. We document the properties of the attached-flow boundary layer on the cylinder surface as these vary with . Within the separated portion of the flow, mean-flow separation-reattachment bubbles are observed at some values of , with separation characteristics that are consistent with experimental observations. Time sequences of instantaneous surface portraits of vector skin-friction trajectory fields indicate that the unsteady counterpart of a mean-flow separation-reattachment bubble corresponds to the formation of local flow-reattachment cells, visible as coherent bundles of diverging surface streamlines.
KAUST Department:
Mechanical Engineering Program; Physical Sciences and Engineering (PSE) Division
Citation:
Cheng W, Pullin DI, Samtaney R, Zhang W, Gao W (2017) Large-eddy simulation of flow over a cylinder with from to : a skin-friction perspective. Journal of Fluid Mechanics 820: 121–158. Available: http://dx.doi.org/10.1017/jfm.2017.172.
Publisher:
Cambridge University Press (CUP)
Journal:
Journal of Fluid Mechanics
KAUST Grant Number:
URF/1/1394-01; URF/1/1394-01
Issue Date:
5-May-2017
DOI:
10.1017/jfm.2017.172
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. The Cray XC40, Shaheen, at KAUST was utilized for all of the reported LES.
Additional Links:
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/largeeddy-simulation-of-flow-over-a-cylinder-with-red-from-39times-103-to-85times-105-a-skinfriction-perspective/22AFE6775E5449F769DF5653089CFE0A
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorCheng, Wanen
dc.contributor.authorPullin, D. I.en
dc.contributor.authorSamtaney, Ravien
dc.contributor.authorZhang, W.en
dc.contributor.authorGao, Weien
dc.date.accessioned2017-05-31T11:23:10Z-
dc.date.available2017-05-31T11:23:10Z-
dc.date.issued2017-05-05en
dc.identifier.citationCheng W, Pullin DI, Samtaney R, Zhang W, Gao W (2017) Large-eddy simulation of flow over a cylinder with from to : a skin-friction perspective. Journal of Fluid Mechanics 820: 121–158. Available: http://dx.doi.org/10.1017/jfm.2017.172.en
dc.identifier.issn0022-1120en
dc.identifier.issn1469-7645en
dc.identifier.doi10.1017/jfm.2017.172en
dc.identifier.urihttp://hdl.handle.net/10754/623860-
dc.description.abstractWe present wall-resolved large-eddy simulations (LES) of flow over a smooth-wall circular cylinder up to , where is Reynolds number based on the cylinder diameter and the free-stream speed . The stretched-vortex subgrid-scale (SGS) model is used in the entire simulation domain. For the sub-critical regime, six cases are implemented with . Results are compared with experimental data for both the wall-pressure-coefficient distribution on the cylinder surface, which dominates the drag coefficient, and the skin-friction coefficient, which clearly correlates with the separation behaviour. In the super-critical regime, LES for three values of are carried out at different resolutions. The drag-crisis phenomenon is well captured. For lower resolution, numerical discretization fluctuations are sufficient to stimulate transition, while for higher resolution, an applied boundary-layer perturbation is found to be necessary to stimulate transition. Large-eddy simulation results at , with a mesh of , agree well with the classic experimental measurements of Achenbach (J. Fluid Mech., vol. 34, 1968, pp. 625-639) especially for the skin-friction coefficient, where a spike is produced by the laminar-turbulent transition on the top of a prior separation bubble. We document the properties of the attached-flow boundary layer on the cylinder surface as these vary with . Within the separated portion of the flow, mean-flow separation-reattachment bubbles are observed at some values of , with separation characteristics that are consistent with experimental observations. Time sequences of instantaneous surface portraits of vector skin-friction trajectory fields indicate that the unsteady counterpart of a mean-flow separation-reattachment bubble corresponds to the formation of local flow-reattachment cells, visible as coherent bundles of diverging surface streamlines.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. The Cray XC40, Shaheen, at KAUST was utilized for all of the reported LES.en
dc.publisherCambridge University Press (CUP)en
dc.relation.urlhttps://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/largeeddy-simulation-of-flow-over-a-cylinder-with-red-from-39times-103-to-85times-105-a-skinfriction-perspective/22AFE6775E5449F769DF5653089CFE0Aen
dc.subjectboundary layer separationen
dc.subjectBoundary layersen
dc.subjectturbulence simulationen
dc.titleLarge-eddy simulation of flow over a cylinder with from to : a skin-friction perspectiveen
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 Technology, CA, 91125, , United Statesen
kaust.authorCheng, Wanen
kaust.authorSamtaney, Ravien
kaust.authorZhang, W.en
kaust.authorGao, Weien
kaust.grant.numberURF/1/1394-01en
kaust.grant.numberURF/1/1394-01en
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