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Simulation of turbulent flow over roughness strips

Neuhauser, Jonathan ORCID iD icon 1; Schäfer, Kay ORCID iD icon 1; Gatti, Davide 1; Frohnapfel, Bettina ORCID iD icon 1
1 Institut für Strömungsmechanik (ISTM), Karlsruher Institut für Technologie (KIT)

Abstract:

Heterogeneous roughness in the form of streamwise aligned strips is known to generate large scale secondary motions under turbulent flow conditions that can induce the intriguing feature of larger flow rates above rough than smooth surface parts. The hydrodynamical definition of a surface roughness includes a large scale separation between the roughness height and the boundary layer thickness which is directly related to the fact that the drag of a laminar flow is not altered by the presence of roughness. Existing simplified approaches for direct numerical simulation of roughness strips do not fulfil this requirement of an unmodified laminar base flow compared with a smooth wall reference. It is shown that disturbances induced in a modified laminar base flow can trigger large-scale motions with resemblance to turbulent secondary flow. We propose a simple roughness model that allows us to capture the particular features of turbulent secondary flow without impacting the laminar base flow. The roughness model is based on the prescription of a spanwise slip length, a quantity that can directly be translated into the Hama roughness function for a homogeneous rough surface. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000149790
Veröffentlicht am 15.08.2022
Originalveröffentlichung
DOI: 10.1017/jfm.2022.536
Scopus
Zitationen: 5
Web of Science
Zitationen: 4
Dimensions
Zitationen: 5
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Strömungsmechanik (ISTM)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 25.08.2022
Sprache Englisch
Identifikator ISSN: 0022-1120, 1469-7645, 1750-6859
KITopen-ID: 1000149790
Erschienen in Journal of Fluid Mechanics
Verlag Cambridge University Press (CUP)
Band 945
Seiten Art.-Nr.: A14
Vorab online veröffentlicht am 18.07.2022
Nachgewiesen in Dimensions
Scopus
Web of Science
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