We introduce a novel cut-cell Cartesian grid method that preserves the spectral properties of convection and diffusion. That is, convection is discretised by a skewsymmetric operator and diffusion is approximated by a symmetric positive-definite coefficient matrix. Such a symmetry-preserving discretisation of the Navier-Stokes equations is stable on any grid, and conserves the mass, momentum an...

In the present paper, double-diffusive convection, taking into account Coriolis effects, in a horizontal layer of Brinkman-anisotropic bi-disperse porous medium is analysed. Via linear instability analysis, we find that convection can set through stationary or oscillatory motions and critical Rayleigh numbers for onset secondary flow (steady convection) overstability (oscillatory are determined.

Abstract Double-diffusive systems, such as thermosolutal convection, in which the density depends on two components that diffuse at different rates, are prone to both steady and oscillatory instabilities. Such systems can evolve into layered states, components, also density, adopt a “staircase” profile. Turbulent transport is enhanced significantly state. Here we exploit an analogy between magn...

We investigate the early stages of mass convection in a colloidal suspension at high solutal Rayleigh number Ras. From the time evolution of shadowgraph images and by assuming a diffusive growth of the boundary layers we obtain an indirect measurement of the concentration boundary layer thickness delta* at the onset of convection. We show that the dimensionless boundary layer thickness delta=de...

Variations in temperature and salinity in hypersaline liquid-dominated geothermal systems like the Salton Sea Geothermal System (SSGS) tend to be correlated such that liquid density is relatively constant in the system. The tendency toward small density variations may be due to connectivity with a surrounding regional aquifer at multiple depths in the stratigraphic column. We present numerical ...

A sequence of two- and three-dimensional simulations are conducted for the double-diffusive convection (DDC) flows in diffusive regime subjected to an imposed shear. For a wide range control parameters, sufficiently strong perturbation conductive initial state, staircase-like structures spontaneously develop, with relatively well-mixed layers separated by sharp interfaces enhanced scalar gradie...