Journal ArticleDOI
The dynamics of the head of a gravity current advancing over a horizontal surface
J. E. Simpson,Rex Britter +1 more
TLDR
In this paper, an apparatus in which the head of a gravity current is brought to rest by using an opposing flow and a moving floor and a modified lock exchange flow was used to determine the velocity of advance, rate of mixing between two fluids and the depth of the mixed layer left behind the head and above the following gravity current.Abstract:
The motion behind the head of a gravity current advancing over a no-slip horizontal surface is a complex three-dimensional flow. There is intense mixing between the current and its surroundings and the foremost part of the head is raised above the surface. Experimental results are obtained from (i) an apparatus in which the head is brought to rest by using an opposing flow and a moving floor and (ii) a modified lock exchange flow. The dimensionless velocity of advance, rate of mixing between the two fluids and the depth of the mixed layer left behind the head and above the following gravity current are determined for an extended range of the dimensionless gravity current depth. The mixing between the two fluids is the result of gravitational and shear instabilities at the gravity current head. A semi-empirical analysis is presented to describe the results. The influence of Reynolds number is discussed and comparison with a documented atmospheric flow is presented.read more
Citations
More filters
Journal ArticleDOI
The slumping of gravity currents
Herbert E. Huppert,J. E. Simpson +1 more
TL;DR: In this article, it is shown that the gravity current can pass through three states: a slumping phase, a viscous phase, and a purely inertial phase, where the buoyancy force of the intruding fluid is balanced by the inertial force.
Journal ArticleDOI
The structure and fluid mechanics of turbidity currents: a review of some recent studies and their geological implications
Ben Kneller,Clare Buckee +1 more
TL;DR: The literature on the structure and behaviour of gravity currents is reviewed in this paper, with particular attention to turbidity currents, though reference is also made to comparable behaviour in pyroclastic flows.
Journal ArticleDOI
Analysis and direct numerical simulation of the flow at a gravity-current head. Part 1. Flow topology and front speed for slip and no-slip boundaries
TL;DR: In this paper, a detailed analysis of the flow structure at the foremost part of the front, where no previous high-resolution data were available, was performed, based on spectral and spectral-element discretizations and compact finite differences.
Journal ArticleDOI
Gravity currents produced by instantaneous releases of a heavy fluid in a rectangular channel
James W. Rottman,J. E. Simpson +1 more
TL;DR: In this paper, a finite volume of homogeneous fluid was released instantaneously into another fluid of slightly lower density and the experiments were performed in a channel of rectangular cross-section, and the two fluids used were salt water and fresh water.
Journal ArticleDOI
Gravity currents produced by lock exchange
TL;DR: In this paper, it was shown that dissipation is not important at high Reynolds number, and provided an alternative theory that predicts the current speed and depth based on energy-conserving flow that is in good agreement with experiments.
References
More filters
Book
Buoyancy Effects in Fluids
TL;DR: In this article, the authors introduce linear internal waves and herar flows in a stratified fluid and double-diffusive convection in stably stratified fluids, and show that the shear flows can produce turbulence.
Journal ArticleDOI
Gravity currents and related phenomena
TL;DR: In this paper, the authors present a broad investigation into the properties of steady gravity currents, in so far as they can be represented by perfect-fluid theory and simple extensions of it (like the classical theory of hydraulic jumps) that give a rudimentary account of dissipation.
Journal ArticleDOI
Oil Spreading on the Sea
TL;DR: The drift due to wind may be estimated by arg uin g that the turbulent shear-stress law at the water interface is approximately the same in both the air and the water as discussed by the authors.
Journal ArticleDOI
The engineer grapples with nonlinear problems
TL;DR: The most important engineering problems and the mathematical concepts and methods involved in their treatment are indicated in the following table as discussed by the authors ; however, it is not possible to give an exhaustive list of all types of problems which require the applications of advanced analytical methods.
Related Papers (5)
Gravity currents produced by instantaneous releases of a heavy fluid in a rectangular channel
James W. Rottman,J. E. Simpson +1 more