This paper considers ‘diffusion-driven flows’, for which a temperature flux condition on a sloping non-slip surface in a stratified fluid generates a slow steady upward flow along a thin ‘buoyancy layer’. The principles for this steady-flow phenomenon are well-understood in a semi-infinite fluid and more recently have been applied to steady flows within a contained fluid under more general cond...

A weak instability mode, associated with phase-locked counterpropagating coastal Kelvin waves in horizontal anticyclonic shear, is found in the semigeostrophic (SG) equations for stratified flow in a channel. This SG instability mode approximates a similar mode found in the Euler equations in the limit in which particle-trajectory slopes are much smaller than f /N, where f is the Coriolis frequ...

Scaling relationships are proposed for the turbulent katabatic flow of a stably stratified fluid down a homogeneously cooled planar slope—the turbulent analogue of a Prandtl-type slope flow. The Theorem predicts that such flows are controlled by three nondimensional parameters: the slope angle, the Prandtl number, and a Reynolds number defined in terms of the surface thermal forcing (surface bu...

The equations of motion are solved numerically for a Boussinesq fluid with infinite Prandtl number in a square 2-D box where the viscosity increases with depth. Three heating modes are employed: bottom heating, internal heating, and half bottom and half internal heating. In all cases the boundaries are free slip. The range of Rayleigh numbers employed is 10-107. The viscosity increases as 10{3(...

This paper theoretically and experimentally investigates the exchange flow due to temperature differences between open water and a canopy of aquatic plants. A numerical model is used to study the interfacial shape, frontal velocity and total volumetric exchange, and their dependence on a dimensionless vegetation drag parameter. The numerical predictions are consistent with the laboratory measur...

– The cuttlefish’s inner shell, better known under the name “cuttlebone”, is a complex structure that has been studied by scientists since nearly two centuries. indeed, this shell which is involved in tissue support and buoyancy regulation unites useful properties such as high mechanical resistance, porosity and permeability. Moreover, this ostensibly straight shell is unique in extant and know...

Previous theoretical work has speculated about the existence of doublediffusive magnetic buoyancy instabilities of a dynamically evolving horizontal magnetic layer generated by the interaction of forced vertically sheared velocity and a background vertical magnetic field. Here we confirm numerically that if the ratio of the magnetic to thermal diffusivities is sufficiently low then such instabi...

The paper describes a modeling study of heat transfer and buoyancy-driven airflow in double skin facades consisting of a glass outer layer, a control device (venetian blind) and a double-glazed inner skin. The modeling study was based on two approaches — a component-based, lumped parameter simulation which used a public domain, open source differential/algebraic equation solver and a detailed, ...

The writers present a one-dimensional integral model to describe multiphase plumes discharged to quiescent stratified receiving waters. The model includes an empirical submodel for detrainment, and the capability to include dispersed phase dissolution. Model equations are formulated by conservation of mass, momentum, heat, dissolved species concentration, and salinity, and allow the tracking of...

Boundary layers driven by surface buoyant forcings are commonly observed in the environmental flows. An atmospheric example of such boundary layer is the so-called convective boundary layer (CBL), which is driven by buoyancy production at the heated underlying surface during the daytime conditions. The buoyancy is defined as b= g − ( ρ -ρ0 )/ρ0 , where ρ is the density of the fluid, ρ0 is the r...