ERA

Download the full-sized PDF of Gravity currents in two-layer stratified mediaDownload the full-sized PDF

Analytics

Share

Permanent link (DOI): https://doi.org/10.7939/R3HH0P

Download

Export to: EndNote  |  Zotero  |  Mendeley

Communities

This file is in the following communities:

Graduate Studies and Research, Faculty of

Collections

This file is in the following collections:

Theses and Dissertations

Gravity currents in two-layer stratified media Open Access

Descriptions

Other title
Subject/Keyword
Long wave
Bore
Internal wave
Gravity current
Stratification
Type of item
Thesis
Degree grantor
University of Alberta
Author or creator
Tan, Alan
Supervisor and department
Flynn, Morris (Mechanical Engineering)
Fleck, Brian (Mechanical Engineering)
Examining committee member and department
Nobes, David (Mechanical Engineering)
Sutherland, Bruce (Department of Mathematical and Statistical Sciences)
Department
Department of Mechanical Engineering
Specialization

Date accepted
2011-01-06T22:10:03Z
Graduation date
2011-06
Degree
Master of Science
Degree level
Master's
Abstract
An analytical and experimental study of boundary gravity currents propagating through a two-layer stratified ambient of finite vertical extent is presented. The theoretical discussion considers slumping, supercritical gravity currents, i.e. those that generate an interfacial disturbance whose speed of propagation matches the front speed, U and follows from the classical analysis of Benjamin [J. Fluid Mech. 31, pp. 209-248, 1968]. In contrast to previous investigations, the amplitude of the interfacial disturbance is parameterized so that it can be determined straightforwardly from ambient layer depths. The theoretical model, which is applicable to the special case where the depth, D, of the gravity current fluid at the initial instant spans the channel depth, H, shows good agreement with experimental measurements and also analogue numerical simulations performed in conjunction with the present investigation. Unfortunately, it is difficult to extend our theoretical results to the more general case where D < H. Reasons for this difficulty will be discussed. From experimental and numerical observations, the interface thickness is observed to negligibly affect the speed of supercritical gravity currents even in the limit where the interface spans the channel depth so that the ambient fluid is linearly stratified over the whole of its depth. Conversely, subcritical gravity currents show a mild upward trend of U on the interface thickness. Finally, the effects of densities, ambient depths, interface thickness and D on the horizontal position, X where deceleration first begins are considered. In contrast to the uniform ambient configuration, the gravity current can propagate without decelerating beyond 12 lock lengths and decelerate as early as 1 lock length.
Language
English
DOI
doi:10.7939/R3HH0P
Rights
License granted by Alan Tan (awtan@ualberta.ca) on 2011-01-06T01:24:00Z (GMT): Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of the above terms. The author reserves all other publication and other rights in association with the copyright in the thesis, and except as herein provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
2014-05-01T01:50:40.079+00:00
Audit Status
Audits have not yet been run on this file.
Characterization
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 8608851
Last modified: 2015:10:12 13:40:28-06:00
Filename: Tan_Alan_2011.pdf
Original checksum: bb989e2ff4ad1e4b78df761a132a197a
Well formed: true
Valid: true
Page count: 106
Activity of users you follow
User Activity Date