Turbulent/turbulent entrainment in a planar wake
File(s)
Published version
Author(s)
Buxton, Oliver
Chen, Jiangang
Type
Conference Paper
Abstract
Spatially-evolving turbulent/turbulent interfaces (TTIs), demarcating a turbulent wake from decaying background turbulence, are studied alongside the entrainment behaviour between these two adjacent streams of turbulence. Data is acquired experimentally in which a cylinder is placed downstream of a turbulence-generating grid. Various “flavours” of background turbulence are generated by varying the type of grid and the grid – cylinder separation. Scalar is seeded into the wake and planar laser induced fluorescence (PLIF) is used to distinguish the wake from the background and hence identify the instantaneous location of the TTI. Simultaneous particle image velocimetry (PIV) measurements are conducted to examine the velocity/vorticity fields. Our results show that similarly to turbulent/non-turbulent interfaces (TNTIs) TTIs manifest as a rapid jump in the enstrophy across a short distance. The presence of background turbulence is shown to potentially enhance the entrainment velocity in the near wake, but it substantially suppresses it in the far wake, with the background turbulence intensity being of greatest significance. This affects the entrainment fluxes of mass, momentum, and kinetic energy into the wake, but these fluxes depend on both the entrainment velocity and the surface area of the TTI over which entrainment takes place, which is quantified through the spatially-evolving fractal dimension of the TTI.
Date Issued
2026-02-18
Date Acceptance
2026-02-18
Citation
2026, 3173, pp.1-11
ISSN
1742-6588
Publisher
Journal of Physics: Conference Series
Start Page
1
End Page
11
Journal / Book Title
Journal of Physics: Conference Series
Volume
3173
Issue
1
Copyright Statement
Content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd.
License URL
Source
11th iTi conference on turbulence 2025
Publication Status
Published
Start Date
2025-07-27
Finish Date
2025-07-30
Coverage Spatial
Bertinoro, Italy
Date Publish Online
2026-02-18