Convection of the 3000 km thick rocky mantle and the liquid iron core below it are the two most important large-scale dynamical processes in Earth’s interior. Two computer codes using different numerical techniques (spectral and multigrid) have been developed for modeling convection in these two quite different environments, in three-dimensional spherical geometry. Under the NASA HPCC program t...

Several computational experiments were carried out with a state-of-the-art ocean general circulation model to identify the northward directed Ekman transport of Antarctic and Subantarctic origin surface water as a mechanism which forces mid-latitude convection. The results indicate that the wind-driven transport of water in the surface layer is most efficient at increasing the depth of convecti...

This paper qualifies the effect of different convection schemes and center-domains on the simulation of winter precipitation over Iran using RegCM3 numerical climate model. It is compressible, finite difference with hydrostatic equilibrium in sigma coordinate with a semi-implicit algorithm for reduction of horizontal diffusion. Iran experienced two dry and wet periods during winters of 1997 and...

On the onset of triple-diffusive convection in a horizontal layer of nanofluid heated from below and salted from above and below is studied both analytically and numerically. The effects of thermophoresis and Brownian diffusion parameters are also introduced through Buongiorno model in the governing equations. By using linear stability analysis based on perturbation theory and applying normal m...

Nonlinear thermal convection in a spherical fluid layer in the presence of spherically symmetric gravity, spherical RayleighBénard convection, is investigated. At the onset of spherical Rayleigh-Bénard convection, there exists the (2l+1)-fold degeneracy of the linear solution, where l is the degree of a spherical harmonics. Nonlinear convection is studied through fully three-dimensional numeric...

The dispersion behavior of solutes was investigated in a rotating flowing coiled tube. Potassium iodide, tartrazine, ascorbic acid, lysozyme, bovine serum albumin (BSA), and silver nanoparticle (AgNPs) samples were eluted in a coiled tube of counter-current chromatography (CCC) apparatus with a single phase. Apparent convection peaks of low-diffusivity solutes appeared in the static CCC tube, w...

The resonant-mass technique for the detection of Gravitational Waves may involve, in the near future, the cooling of very large masses (about 100 tons) from room temperature (300K) to extreme cryogenic temperatures (20mK). To cool these detectors down to cryogenic temperatures an exchange gas (helium) is used, and the heat is removed from the antenna to the cold reservoir by thermal conduction ...

the fluid flow and heat transfer in a three-dimensional microchannel filled with al2o3- water nanofluid is numerically investigated. the hybrid scheme is used to discretize the convection terms and simpler algorithm is adopted to couple the velocity and pressure field in the momentum equations. the temperature fields, variation of horizontal velocity along the centre line of the channel, averag...

Adiabatic compression is a key factor that exerts control over thermal convection in the compressible solid mantle of super-Earths. To discuss the effects of adiabatic compression, we present a numerical model of transient convection in the cooling mantle of a super-Earth that is ten times larger in size than the Earth. The calculations started with the shallow mantle that was hotter than expec...

Numerical solutions of convection–diffusion equations obtained using the Streamline–Upwind Petrov–Galerkin (SUPG) stabilisation typically possess spurious oscillations at layers. Spurious Oscillations at Layers Diminishing (SOLD) methods aim to suppress or at least diminish these oscillations without smearing the layers extensively. In the recent review by John and Knobloch (2007), numerical st...