Turbulence within inertia-buoyancy balanced axisymmetric intrusions

C. J. Lemckert, J. Imberger

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Data from two detailed field experiments were used to investigate the turbulence within inertia-buoyancy balanced, axisymmetric intrusive gravity currents entering nearly quiescent stratified water bodies. The intrusions were generated by energetic point source bubble plume systems installed within different freshwater reservoirs, and the mixing activity was recorded with microstructure profilers. Close to the bubble plume, the intrusions were found to be very turbulent. The turbulent activity within the intrusions was observed to decay most rapidly in the intrusion core, but the shear at the upper and lower boundaries of the intrusions maintained the turbulence in these regions for a long distance. The results showed that the turbulence began with a length scale equal to the maximum sustainable overturn length for internally generated shear and hence a turbulent Froude number near unity, but the Reynolds number decreased with distance; the shear generated by the intrusion thus sustained an active turbulence field, albeit with ever decreasing length scales

Original languageEnglish
Pages (from-to)22649-22666
Number of pages17
JournalJournal of Geophysical Research
Volume100
Issue numberC11
Publication statusPublished - 1995
Externally publishedYes

Fingerprint

Buoyancy
intrusion
buoyancy
inertia
shear stress
Turbulence
turbulence
bubbles
shear
gravity
microstructure
body water
Froude number
plumes
bubble
plume
deterioration
Gravitation
Reynolds number
overturn

Cite this

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abstract = "Data from two detailed field experiments were used to investigate the turbulence within inertia-buoyancy balanced, axisymmetric intrusive gravity currents entering nearly quiescent stratified water bodies. The intrusions were generated by energetic point source bubble plume systems installed within different freshwater reservoirs, and the mixing activity was recorded with microstructure profilers. Close to the bubble plume, the intrusions were found to be very turbulent. The turbulent activity within the intrusions was observed to decay most rapidly in the intrusion core, but the shear at the upper and lower boundaries of the intrusions maintained the turbulence in these regions for a long distance. The results showed that the turbulence began with a length scale equal to the maximum sustainable overturn length for internally generated shear and hence a turbulent Froude number near unity, but the Reynolds number decreased with distance; the shear generated by the intrusion thus sustained an active turbulence field, albeit with ever decreasing length scales",
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Turbulence within inertia-buoyancy balanced axisymmetric intrusions. / Lemckert, C. J.; Imberger, J.

In: Journal of Geophysical Research, Vol. 100, No. C11, 1995, p. 22649-22666.

Research output: Contribution to journalArticle

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AU - Imberger, J.

PY - 1995

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