Change search
ReferencesLink to record
Permanent link

Direct link
Stability analysis of experimental flow fields behind a porous cylinder for the investigation of the large-scale wake vortices
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.ORCID iD: 0000-0002-3251-8328
2013 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 715, 499-536 p.Article in journal (Refereed) Published
Abstract [en]

When the linear stability analysis is applied to the time-averaged flow past a circular cylinder after the primary instability of the wake, a nearly marginally stable global mode is predicted with a frequency in time equal to that of the saturated vortex shedding. This behaviour has recently been shown to hold up to Reynolds number Re = 600 by direct numerical simulations. In the present work we verify that the global stability analysis provides reasonable estimation also when applied to experimental velocity fields measured in the wake past a porous circular cylinder at Re similar or equal to 3.5 x 10(3). Different intensities of continuous suction and blowing through the entire surface of the cylinder are considered. The global direct and adjoint stability modes, derived from the experimental data, are used to sort the random instantaneous snapshots of the velocity field in phase. The proposed method is remarkable, sorting the snapshots in phase with respect to the vortex shedding, allowing phase-averaged velocity fields to be extracted from the experimental database. The phase-averaged flow fields are analysed in order to study the effect of the transpiration on the kinematical characteristics of the large-scale wake vortices.

Place, publisher, year, edition, pages
2013. Vol. 715, 499-536 p.
Keyword [en]
instability, vortex shedding, wakes/jets
National Category
Engineering and Technology
URN: urn:nbn:se:kth:diva-118607DOI: 10.1017/jfm.2012.532ISI: 000313588800020OAI: diva2:607201
Swedish Research Council

QC 20130222

Available from: 2013-02-22 Created: 2013-02-21 Last updated: 2013-02-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Fallenius, Bengt E. G.Fransson, Jens H. M.
By organisation
MechanicsLinné Flow Center, FLOW
In the same journal
Journal of Fluid Mechanics
Engineering and Technology

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: 30 hits
ReferencesLink to record
Permanent link

Direct link