Mixing by shear instability at high Reynolds number
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In this paper, the authors show that the mixing induced by shear instability at high Reynolds number does not primarily occur by overturning in the cores; rather it results from secondary shear instabilities within the zones of intensified shear separating the cores.Abstract:
[1] Shear instability is the dominant mechanism for converting fluid motion to mixing in the stratified ocean and atmosphere. The transition to turbulence has been well characterized in laboratory settings and numerical simulations at moderate Reynolds number—it involves “rolling up”, i.e., overturning of the density structure within the cores of the instabilities. In contrast, measurements in an energetic estuarine shear zone reveal that the mixing induced by shear instability at high Reynolds number does not primarily occur by overturning in the cores; rather it results from secondary shear instabilities within the zones of intensified shear separating the cores. This regime is not likely to be observed in the relatively low Reynolds number flows of the laboratory or in direct numerical simulations, but it is likely a common occurrence in the ocean and atmosphere.read more
Citations
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References
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Journal ArticleDOI
On the stability of heterogeneous shear flows
TL;DR: In this paper, small perturbations of a parallel shear flow U(y) in an inviscid, incompressible fluid of variable density ρ 0 (y) are considered.
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Numerical studies of the stability of inviscid stratified shear flows
TL;DR: In this paper, the Taylor-Goldstein equation is used to describe the stability of inviscid, parallel, stratified shear flows to two-dimensional disturbances, and two computer programs are developed to integrate the stability equation and to solve for eigenvalues.
Journal ArticleDOI
Structure and Generation of Turbulence at Interfaces Strained by Internal Solitary Waves Propagating Shoreward over the Continental Shelf
TL;DR: In this article, the structure within internal solitary waves propagating shoreward over Oregon's continental shelf is studied. But the authors focus on the evolving nature of interfaces as they become unstable and break, creating turbulent flow.
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The Efficiency of Mixing in Turbulent Patches: Inferences from Direct Simulations and Microstructure Observations
TL;DR: The time evolution of mixing in turbulent overturns using a combination of direct numerical simulations (DNS) and microstructure profiles obtained during two field experiments is investigated in this article, where the focus is on the flux coefficient G, the ratio of the turbulent buoyancy flux to the turbulent kinetic energy dissipation rate.
Journal ArticleDOI
Experiments on instability and turbulence in a stratified shear flow
TL;DR: In this paper, a study of turbulence which results from Kelvin-Helmholtz instability at the interface between two miscible fluids in a two-dimensional shear flow in the laboratory is described.