Change search
ReferencesLink to record
Permanent link

Direct link
The effect of surface roughness on the convective instability of the BEK family of boundary-layer flows
KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.ORCID iD: 0000-0001-8667-0520
2016 (English)In: European journal of mechanics. B, Fluids, ISSN 0997-7546, E-ISSN 1873-7390, Vol. 56, 178-187 p.Article in journal (Refereed) PublishedText
Abstract [en]

A Chebyshev polynomial discretisation method is used to investigate the effect of both anisotropic (radially and azimuthally) and isotropic surface roughnesses on the convective instability of the BEK family of rotating boundary-layer flows. The mean-flow profiles for the velocity components are obtained by modelling surface roughness with a partial-slip approach. A linear stability analysis is then performed to investigate the effect of roughness on the convective instability characteristics of the inviscid Type I (cross-flow) instability and the viscous Type II instability. It is revealed that all roughness types lead to a stabilisation of the Type I mode in all flows within the BEK family, with the exception of azimuthally-anisotropic roughness (radial grooves) within the Bödewadt layer which causes a mildly destabilising effect. In the case of the Type II mode, the results reveal the destabilising effect of radially-anisotropic roughness (concentric grooves) on all the boundary layers, whereas both azimuthally-anisotropic and isotropic roughnesses have a stabilising effect on the mode for Ekman and von Kármán layers. Complementary results are also presented by considering the effects of roughness on the growth rates of each instability mode within the Ekman layer.

Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 56, 178-187 p.
Keyword [en]
Boundary layer, Flow control, Linear-stability analysis, Rotation, Roughness, Transition
National Category
Fluid Mechanics and Acoustics
Identifiers
URN: urn:nbn:se:kth:diva-180909DOI: 10.1016/j.euromechflu.2015.11.013ISI: 000378100300016ScopusID: 2-s2.0-84953791139OAI: oai:DiVA.org:kth-180909DiVA: diva2:898497
Note

QC 20160128

Available from: 2016-01-28 Created: 2016-01-25 Last updated: 2016-07-11Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Segalini, Antonio
By organisation
Fluid PhysicsLinné Flow Center, FLOW
In the same journal
European journal of mechanics. B, Fluids
Fluid Mechanics and Acoustics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 65 hits
ReferencesLink to record
Permanent link

Direct link