Stratified flow
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Layering, Instabilities, and Mixing in Turbulent Stratified Flows Open
Understanding how turbulence leads to the enhanced irreversible transport of heat and other scalars such as salt and pollutants in density-stratified fluids is a fundamental and central problem in geophysical and environmental fluid dynami…
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Review of wave‐turbulence interactions in the stable atmospheric boundary layer Open
Flow in a stably stratified environment is characterized by anisotropic and intermittent turbulence and wavelike motions of varying amplitudes and periods. Understanding turbulence intermittency and wave‐turbulence interactions in a stably…
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Marangoni flow at droplet interfaces: Three-dimensional solution and applications Open
The Marangoni effect refers to fluid flow induced by a gradient in surface tension at a fluid-fluid interface. We determine the full three-dimensional Marangoni flow generated by a non-uniform surface tension profile at the interface of a …
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Mixing efficiency in stratified turbulence Open
We consider mixing of the density field in stratified turbulence and argue that, at sufficiently high Reynolds numbers, stationary turbulence will have a mixing efficiency and closely related mixing coefficient described solely by the turb…
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Resolving the Paradox of Oceanic Large-Scale Balance and Small-Scale Mixing Open
A puzzle of oceanic dynamics is the contrast between the observed geostrophic balance, involving gravity, pressure gradient, and Coriolis forces, and the necessary turbulent transport: in the former case, energy flows to large scales, lead…
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Hamiltonian Formulation for Wave-Current Interactions in Stratified Rotational Flows Open
We show that the Hamiltonian framework permits an elegant formulation of the nonlinear governing equations for the coupling between internal and surface waves in stratified water flows with piecewise constant vorticity.
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Flow regimes for fluid injection into a confined porous medium Open
We report theoretical and numerical studies of the flow behaviour when a fluid is injected into a confined porous medium saturated with another fluid of different density and viscosity. For a two-dimensional configuration with point source…
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Flow dynamics and mixing processes in hydraulic jump arrays: Implications for channel-lobe transition zones Open
A detailed field investigation of a saline gravity current in the southwest Black Sea has enabled the first complete analysis of three-dimensional flow structure and dynamics of a series of linked hydraulic jumps in,stratified, density-dri…
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Are geomagnetic data consistent with stably stratified flow at the core–mantle boundary? Open
Recent first principles calculations of the Earth's outer core thermal and electrical conductivities have raised their values by a factor of three. This has significant implications for geodynamo operation, in particular, forcing the devel…
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Evidence for Bolgiano-Obukhov scaling in rotating stratified turbulence using high-resolution direct numerical simulations Open
We report results on rotating stratified turbulence in the absence of forcing and with large-scale isotropic initial conditions using direct numerical simulations computed on grids of up to 40963 points. The Reynolds and Froude numbers are…
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Vertical drafts and mixing in stratified turbulence: Sharp transition with Froude number Open
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Revisiting Bolgiano–Obukhov scaling for moderately stably stratified turbulence Open
According to the celebrated Bolgiano–Obukhov (Bolgiano, J. Geophys. Res. , vol. 64 (12), 1959, pp. 2226–2229; Obukhov, Dokl. Akad. Nauk SSSR , vol. 125, 1959, p. 1246) phenomenology for moderately stably stratified turbulence, the energy s…
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Shell model for buoyancy-driven turbulence Open
In this paper we present a unified shell model for stably stratified and convective turbulence. Numerical simulation of this model for stably stratified flow shows Bolgiano-Obukhbov scaling in which the kinetic energy spectrum varies as k(…
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Forcing homogeneous turbulence in direct numerical simulation of particulate flow with interface resolution and gravity Open
We consider the case of finite-size spherical particles which are settling under gravity in a homogeneous turbulent background flow. Turbulence is forced with the aid of the random forcing method of Eswaran and Pope [“An examination of for…
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Gravity currents flowing upslope: Laboratory experiments and shallow-water simulations Open
This paper investigates the dynamics of lock-release gravity currents propagating upslope by laboratory experiments and shallow-water simulations. Both the interface between the dense and the ambient fluid and the instantaneous velocity fi…
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Tidally driven mixing and dissipation in the stratified boundary layer above steep submarine topography Open
A tidally driven, stratified boundary layer over supercritical topography is simulated numerically. The near‐boundary flow is characterized by quasiperiodic, bore‐like motions and episodic expulsion events where fluid is ejected into the s…
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A comprehensive mathematical structuring of magnetically effected Sutterby fluid flow immersed in dually stratified medium under boundary layer approximations over a linearly stretched surface Open
On the implication of tension force, viscoelastic materials deform in accordance with viscous and elastic characterization. Dilute polymer solutions portray the examples of viscoelastic liquids and Sutterby model successfully represent it …
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Stratification Effects on Flow Hydrodynamics and Mixing at a Confluence With a Highly Discordant Bed and a Relatively Low Velocity Ratio Open
The effects of temperature induced stratification on flow hydrodynamics, thermal mixing, and the capacity of the flow to entrain sediment at a medium‐size stream confluence with a highly discordant bed are investigated. To isolate the effe…
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Dynamics of stratified turbulence decaying from a high buoyancy Reynolds number Open
We present direct numerical simulations (DNS) of unforced stratified turbulence with the objective of testing the strongly stratified turbulence theory. According to this theory the characteristic vertical scale of the turbulence is given …
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Role of overturns in optimal mixing in stratified mixing layers Open
Turbulent mixing plays a major role in enabling the large-scale ocean circulation. The accuracy of mixing rates estimated from observations depends on our understanding of basic fluid mechanical processes underlying the nature of turbulenc…
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Turbulence and Mixing in a Shallow Shelf Sea From Underwater Gliders Open
The seasonal thermocline in shallow shelf seas acts as a natural barrier for boundary‐generated turbulence, damping scalar transport to the upper regions of the water column and controlling primary production to a certain extent. To better…
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Thermohaline layering in dynamically and diffusively stable shear flows Open
In this study we examine two-component shear flows that are stable with respect to Kelvin–Helmholtz and to double-diffusive instabilities individually. Our focus is on diffusively stratified ocean regions, where relatively warm and salty w…
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Vortex Structures in the Wake of an Idealized Seamount in Rotating, Stratified Flow Open
We present the results of a 3‐D computational model of an idealized seamount in rotating, stratified flow. The emergent vortex structures in the lee of the seamount indicate that the vertical coherence of vortices is strongly dependent on …
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Experiments on the structure and stability of mode-2 internal solitary-like waves propagating on an offset pycnocline Open
The structure and stability of mode-2 internal solitary-like waves is investigated experimentally. A rank-ordered train of mode-2 internal solitary waves is generated using a lock release configuration. The pycnocline is centred either on …
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The structure and origin of confined Holmboe waves Open
Finite-amplitude manifestations of stratified shear flow instabilities and their spatio-temporal coherent structures are believed to play an important role in turbulent geophysical flows. Such shear flows commonly have layers separated by …
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Motion in Stratified Fluids Open
Density stratification due to temperature or salinity variations greatly influences the flow around and the sedimentation of objects such as particles, drops, bubbles, and small organisms in the atmosphere, oceans, and lakes. Density strat…
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Layer formation in horizontally forced stratified turbulence: connecting exact coherent structures to linear instabilities Open
We consider turbulence in a stratified ‘Kolmogorov’ flow, driven by horizontal shear in the form of sinusoidal body forcing in the presence of an imposed background linear stable stratification in the third direction. This flow configurati…
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Transport of particles, drops, and small organisms in density stratified fluids Open
Sedimenting particles and motile organisms are ubiquitously found in oceans and lakes, where density stratification naturally occurs due to temperature or salinity gradients. We explore the effects of stratification on the fundamental hydr…
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Temperature and Concentration Stratification Effects in Mixed Convection Flow of an Oldroyd-B Fluid with Thermal Radiation and Chemical Reaction Open
This research addresses the mixed convection flow of an Oldroyd-B fluid in a doubly stratified surface. Both temperature and concentration stratification effects are considered. Thermal radiation and chemical reaction effects are accounted…
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Stratified Flow of Micropolar Nanofluid over Riga Plate: Numerical Analysis Open
In this article, we present a numerical analysis of the energy and mass transport behavior of microrotational flow via Riga plate, considering suction or injection and mixed convection. The thermal stratified parameters of nanofluid are ca…