Vertically distributed wall-sources of buoyancy. Part 1: Unconfined
File(s)
Author(s)
Parker, David
Burridge, Henry
Partridge, Jamie
Linden, Paul
Type
Journal Article
Abstract
We examine a turbulent distributed wall-source plume: the flow resulting from a uniform vertical wall-source of buoyancy such as that produced by an evenly heated or cooled vertical wall. The vertically distributed buoyancy source is created by forcing dense saltwater solution through a porous wall. Velocity measurements on a vertical plane normal to the wall are first presented examining the full height of the wall in order to identify the region in which the bulk flow has become fully turbulent, self-similar and reached an invariant balance between the fluxes of volume, momentum and buoyancy. Simultaneousvelocity and buoyancy field measurements are then presented in this region and an en-trainment coefficient of α= 0.068±0.006 is determined. This value is small compared to that of buoyancy-driven unbounded flows, e.g. a free line plume, and we reason this tobe due to the presence of a rigid boundary restricting meandering and turbulence production, rather than the effect of the vertically distributed source of buoyancy. Turbulent velocity and buoyancy statistics are presented and, in order to gain physical insights into the flow behaviour, the results are compared to those of other canonical buoyancy-driven free and wall-bounded flows. We show that the bulk mixing of distributed wall-source plumes can be captured by consideration of the characteristic vertical velocities and a constant entrainment coefficient. This mixing is inhibited both by the presence of a rigid boundary and the reduced characteristic velocities (compared to those of wall line plumes).
Date Issued
2020-11-23
Date Acceptance
2020-07-30
Citation
Journal of Fluid Mechanics, 2020, 907 (A15), pp.A15-1-A15-26
ISSN
0022-1120
Publisher
Cambridge University Press
Start Page
A15-1
End Page
A15-26
Journal / Book Title
Journal of Fluid Mechanics
Volume
907
Issue
A15
Copyright Statement
© The Author(s), 2020. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Engineering & Physical Science Research Council (E
Identifier
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/vertically-distributed-wall-sources-of-buoyancy-part-1-unconfined/67F089C97A39203DC012DCC08550EAAC
Grant Number
EP/R008957/1
Subjects
Fluids & Plasmas
01 Mathematical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2020-11-23