Depth-averaged momentum equation for gravity currents with varying density. Coefficient in pressure term
No Thumbnail Available
Authors
Author (Corporation)
Publication date
31.07.2017
Typ of student thesis
Course of study
Collections
Type
01A - Journal article
Editors
Editor (Corporation)
Supervisor
Parent work
ISH Journal of Hydraulic Engineering
Special issue
DOI of the original publication
Link
Series
Series number
Volume
56
Issue / Number
3
Pages / Duration
424-430
Patent number
Publisher / Publishing institution
Taylor & Francis
Place of publication / Event location
London
Edition
Version
Programming language
Assignee
Practice partner / Client
Abstract
Gravity currents are often modelled by means of shallow water equations (SWEs). In these models, simplifications such as the consideration of a constant layer-averaged density are common. This note presents the complete and general derivation of a 2D depth-averaged momentum equation for gravity currents with density and velocity varying in the bed-normal direction. Special attention is given to the pressure term which is evaluated for constant, linear and exponential density profile. The shape of the density profile has implications for the momentum balance: the assumption of constant density leads to an overestimation of the driving force due to pressure gradient by a factor of 33% for linear density profile and up to 50% for an exponential profile. It also leads to an overestimation of celerity in numerical models based on traditional SWEs by factor of 22% and around 40% for linear end exponential density profiles respectively.
Keywords
Gravity currents, Shallow water equations
Subject (DDC)
624 - Ingenieurbau und Umwelttechnik
Event
Exhibition start date
Exhibition end date
Conference start date
Conference end date
Date of the last check
ISBN
ISSN
2164-3040
Language
English
Created during FHNW affiliation
No
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the complete publication
Open access category
Closed
License
Citation
POKRAJAC, Dubravka, Sara VENULEO und Mário J. FRANCA, 2017. Depth-averaged momentum equation for gravity currents with varying density. Coefficient in pressure term. ISH Journal of Hydraulic Engineering. 31 Juli 2017. Bd. 56, Nr. 3, S. 424–430. DOI 10.1080/00221686.2017.1335245. Verfügbar unter: https://irf.fhnw.ch/handle/11654/46179