Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Vertical spectra of stratified turbulence at large horizontal scales
KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
2017 (English)In: Physical Review Fluids, ISSN 2469-990X, Vol. 2, no 10, article id 104802Article in journal (Refereed) Published
Abstract [en]

Stably stratified turbulence is investigated with the aim of increasing our limited understanding of the vertical structure of this type of turbulent flow. For strongly stratified turbulence there is a theoretical prediction that the energy spectra in the vertical direction of gravity are very steep, possessing the well-known form E-h(k(v)) alpha N(2)kv(-3) , where N is the Brunt-Vaisala frequency and kv is the vertical wave number, but supporting evidence from experiments and numerical simulations is lacking. We conduct direct numerical simulation (DNS) with uniform background stratification and forcing at large scales. In order to consider the large anisotropic scales only, the vertical energy spectra are decomposed into large-scale vertical spectra E-large(k(v)) and small-scale vertical spectra E-small(k(v)) using a horizontal demarcation scale. We find that this approach gives results that are in close agreement with E-large(k(v)) alpha N(2)k(v)(-3) for the DNS runs performed. This result holds approximately over the wave-number range k(b) <= k(v) <= k(oz), where kb is the buoyancy wave number and koz is the Ozmidov wave number, in agreement with theory. Similarly, large-scale vertical spectra of potential energy are found to be E-p,E-large(k(v)) alpha N(2)k(v)(-3) , over a narrower range of wave numbers. The evidence supports the existence of a scale-by-scale balance between inertia and buoyancy occurring in strongly stratified turbulence at large horizontal scales. Finally, the current results are put in the context of ocean turbulence by making a comparison with measurements of vertical shear spectra made in the ocean interior.

Place, publisher, year, edition, pages
American Physical Society, 2017. Vol. 2, no 10, article id 104802
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-217185DOI: 10.1103/PhysRevFluids.2.104802ISI: 000413294700002Scopus ID: 2-s2.0-85036542329OAI: oai:DiVA.org:kth-217185DiVA, id: diva2:1155001
Note

QC 20171106

Available from: 2017-11-06 Created: 2017-11-06 Last updated: 2017-12-18Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Maffioli, Andrea
By organisation
MechanicsLinné Flow Center, FLOW
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 11 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf