Low-dimensional dynamics of a turbulent axisymmetric wake
File(s)
Accepted version
Author(s)
Rigas, G
Oxlade, AR
Morgans, AS
Morrison, JF
Type
Journal Article
Abstract
The coherent structures of a turbulent wake generated behind a bluff three-dimensional axisymmetric body are investigated experimentally at a diameter-based Reynolds number of ∼2×105 . Proper orthogonal decomposition of base pressure measurements indicates that the most energetic coherent structures retain the structure of the symmetry-breaking laminar instabilities and are manifested as unsteady vortex shedding with azimuthal wavenumber 𝑚=±1 . In a rotating reference frame, the shedding preserves the reflectional symmetry and is linked with a reflectionally symmetric mean pressure distribution on the base. Due to a slow rotation of the symmetry plane of the turbulent wake around the axis of the body, statistical axisymmetry is recovered in the time average. The ratio of the time scales associated with the slow rotation of the symmetry plane and the vortex shedding is of order 100.
Date Issued
2014-09-25
Date Acceptance
2014-07-29
Citation
Journal of Fluid Mechanics, 2014, 755 (1), pp.1-11
ISSN
0022-1120
Publisher
Cambridge University Press
Start Page
1
End Page
11
Journal / Book Title
Journal of Fluid Mechanics
Volume
755
Issue
1
Copyright Statement
© 2014 Cambridge University Press . The final publication is available via Cambridge Journals Online at http://dx.doi.org/10.1017/jfm.2014.449
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/lowdimensional-dynamics-of-a-turbulent-axisymmetric-wake/26878C373FA198C8EEBC720BBBC5140F
Grant Number
EP/I005684/1
Subjects
Science & Technology
Technology
Physical Sciences
Mechanics
Physics, Fluids & Plasmas
Physics
turbulent flows
vortex shedding
wakes/jets
BLUFF-BODY
SPHERE
INSTABILITY
STABILITY
DISK
Fluids & Plasmas
01 Mathematical Sciences
09 Engineering
Publication Status
Published
Article Number
R5
Date Publish Online
2014-08-14