An energy analysis of convective instabilities of the Bödewadt and Ekman boundary layers over rough surfaces
2016 (English)In: European journal of mechanics. B, Fluids, ISSN 0997-7546, E-ISSN 1873-7390Article in journal (Refereed) Published
⋯ An energy balance equation for the three-dimensional Bödewadt and Ekman layers of the so called "BEK family" of rotating boundary-layer flows is derived. A Chebyshev discretization method is used to solve the equations and investigate the effect of surface roughness on the physical mechanisms of transition. All roughness types lead to a stabilization of the Type I (cross-flow) instability mode for both flows, with the exception of azimuthally-anisotropic roughness (radial grooves) within the Bödewadt layer which is destabilizing. In the case of the viscous Type II instability mode, the results predict a destabilization effect of radially-anisotropic roughness (concentric grooves) on both flows, whereas both azimuthally-anisotropic roughness and isotropic roughness have a stabilization effect. The results presented here confirm the results of our prior linear stability analyses. © 2016 Elsevier Masson SAS.
Place, publisher, year, edition, pages
BEK family, Energy, Roughness, Anisotropy, Boundary layer flow, Discrete event simulation, Stabilization, Surface roughness, Convective instabilities, Destabilization effects, Discretization method, Ekman boundary layers, Energy balance equations, Stabilization effects, Boundary layers
IdentifiersURN: urn:nbn:se:kth:diva-194587DOI: 10.1016/j.euromechflu.2016.09.006ScopusID: 2-s2.0-84991273900OAI: oai:DiVA.org:kth-194587DiVA: diva2:1044161
Correspondence Address: Alveroglu, B.email: email@example.com. QC 201611022016-11-022016-10-312016-11-02Bibliographically approved