Experimental study of the initial growth of a localized turbulent patch in a stably stratified fluid
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
We present a laboratory experiment of the initial growth of a turbulent patch in a stably stratified fluid. The patch is created due to a localized source of turbulence, generated by a horizontally oriented and vertically oscillating grid much smaller than the tank size and far from solid boundaries. Synchronized and overlapping particle image velocimetry(PIV) and planar laser induced fluorescence (PLIF) measurements capture the evolution of the patch through its initial growth until it reached a maximum size. The simultaneous measurements of density and velocity fields allow for a direct quantification of the distribution of kinetic energy, buoyancy and degree of mixing within the patch. We can also relate the propagation speed of the turbulent/non-turbulent interface and its thickness to the properties of the turbulent fluid inside the evolving patch. The velocity measurements in this setup indicate significant transient effects inside the patch during its growth. A local analysis of the turbulent/non-turbulent interface provides direct measurements of the entrainment velocity we as compared to the local vertical velocity and turbulent intensity at the proximity of the interface. The detailed information about the growth of localized sources of turbulence in stratified environment might be of use in stealth design of autonomous underwater vehicles.
Date Issued
2017-06-13
Date Acceptance
2017-06-08
Citation
International Journal of Heat and Fluid Flow, 2017, 66, pp.127-136
ISSN
0142-727X
Publisher
Elsevier
Start Page
127
End Page
136
Journal / Book Title
International Journal of Heat and Fluid Flow
Volume
66
Copyright Statement
© 2017 Elsevier Inc. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000407524500012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Technology
Thermodynamics
Engineering, Mechanical
Mechanics
Engineering
Turbulent patch
Local entrainment and stable stratification
INTERNAL WAVES
BREAKING
WAKES
FLOW
EVOLUTION
COLLAPSE
REGION
SHEAR
Publication Status
Published