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DC Field | Value | Language |
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dc.citation.number | 1 | - |
dc.citation.startPage | 014608 | - |
dc.citation.title | PHYSICAL REVIEW FLUIDS | - |
dc.citation.volume | 3 | - |
dc.contributor.author | Hwang, Hyeon Gyu | - |
dc.contributor.author | Lee, Jae Hwa | - |
dc.date.accessioned | 2023-12-21T21:13:58Z | - |
dc.date.available | 2023-12-21T21:13:58Z | - |
dc.date.created | 2018-02-08 | - |
dc.date.issued | 2018-01 | - |
dc.description.abstract | Direct numerical simulations of turbulent boundary layers over longitudinal surface roughness are performed to investigate the impact of the surface roughness on the mean flow characteristics related to counter-rotating large-scale secondary flows. By systematically changing the two parameters of the pitch (P) and width (S) for roughness elements in the ranges of 0.57 <= P/delta <= 2.39 and 0.15 <= S/delta <= 1.12, where delta is the boundary layer thickness, we find that the size of the secondary flow in each case is mostly determined by the value of P - S, i.e., the valley width, over the ridge-type roughness. However, the strength of the secondary flows on the cross-stream plane relative to the flow is increased when the value of P increases or when the value of S decreases. In addition to the secondary flows, additional tertiary and quaternary flows are observed both above the roughness crest and in the valley as the values of P and S increase further. Based on an analysis using the turbulent kinetic energy transport equation, it is shown that the secondary flow over the ridge-type roughness is both driven and sustained by the anisotropy of turbulence, consistent with previous observations of a turbulent boundary layer over strip-type roughness [Anderson et al., J. Fluid Mech. 768, 316 (2015)]. Careful inspection of the turbulent kinetic energy budget reveals that the opposite rotational sense of the secondary flow between the ridge- and strip-type roughness elements is primarily attributed to the local imbalance of energy budget created by the strong turbulent transport term over the ridge-type roughness. The active transport of the kinetic energy over the ridge-type roughness is closely associated with the upward deflection of spanwise motions in the valley, mostly due to the roughness edge. | - |
dc.identifier.bibliographicCitation | PHYSICAL REVIEW FLUIDS, v.3, no.1, pp.014608 | - |
dc.identifier.doi | 10.1103/PhysRevFluids.3.014608 | - |
dc.identifier.issn | 2469-990X | - |
dc.identifier.scopusid | 2-s2.0-85041493700 | - |
dc.identifier.uri | https://scholarworks.unist.ac.kr/handle/201301/23663 | - |
dc.identifier.url | https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.3.014608 | - |
dc.identifier.wosid | 000423134700003 | - |
dc.language | 영어 | - |
dc.publisher | AMER PHYSICAL SOC | - |
dc.title | Secondary flows in turbulent boundary layers over longitudinal surface roughness | - |
dc.type | Article | - |
dc.description.isOpenAccess | FALSE | - |
dc.relation.journalWebOfScienceCategory | Physics, Fluids & Plasmas | - |
dc.relation.journalResearchArea | Physics | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.subject.keywordPlus | DIRECT NUMERICAL-SIMULATION | - |
dc.subject.keywordPlus | ROUGHENED WALL | - |
dc.subject.keywordPlus | CHANNEL FLOW | - |
dc.subject.keywordPlus | CURRENTS | - |
dc.subject.keywordPlus | VORTICES | - |
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