Skip to main content Accessibility help
×
Home
Hostname: page-component-59b7f5684b-j5sqr Total loading time: 0.334 Render date: 2022-09-30T23:10:14.803Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "displayNetworkTab": true, "displayNetworkMapGraph": false, "useSa": true } hasContentIssue true

Localized mixing due to a breaking internal wave ray at a sloping bottom

Published online by Cambridge University Press:  10 November 1997

I. P. D. DE SILVA
Affiliation:
Centre for Water Research, Department of Environmental Engineering, The University of Western Australia, Nedlands, Western Australia 6907
J. IMBERGER
Affiliation:
Centre for Water Research, Department of Environmental Engineering, The University of Western Australia, Nedlands, Western Australia 6907
G. N. IVEY
Affiliation:
Centre for Water Research, Department of Environmental Engineering, The University of Western Australia, Nedlands, Western Australia 6907

Abstract

A laboratory experiment was conducted to investigate the characteristics of turbulence generated by an internal wave ray breaking on a sloping bed. The width of the incident wave ray was small compared to the bed length, so that an isolated turbulent patch was generated by the breaking process, a configuration unique to the present study. The parameter range covered subcritical, critical and supercritical frequencies. Flow visualization and velocity measurements revealed that near critical conditions the flow was confined to a narrow region above the bed and, contrary to expectations, critical waves showed a weak turbulence field. Subcritical and supercritical reflection resembled wave–wave interaction between the incident and the reflected waves and showed comparable centred displacement lengthscales. As the incident waves became progressively supercritical instabilities were first initiated away from the bed. For supercritical waves the centred displacement lengthscale and the turbulent Reynolds number both increased steadily up to about γ≈2, after which they started to decrease (γ=ω/ωc, where ω is the frequency of the incident wave and ωc=Nsinβ is the critical frequency for an ambient uniform stratification of magnitude N and a bed angle of β). For subcritical waves an increase in the centred displacement lengthscale and the turbulent Reynolds number was also observed. The mixed fluid generated at the boundary collapsed into the fluid interior in the form of a horizontal two-dimensional viscous–buoyancy intrusion: the efficiency of mixing was, however, very small and no measurable change in the mean density gradient was observed over the duration of the experiments.

Type
Research Article
Copyright
© 1997 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)
59
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Localized mixing due to a breaking internal wave ray at a sloping bottom
Available formats
×

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Localized mixing due to a breaking internal wave ray at a sloping bottom
Available formats
×

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Localized mixing due to a breaking internal wave ray at a sloping bottom
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *