Numerical study of double-diffusive natural convection in a square cavity

A three-dimensional numerical study has been performed to investigate double-diffusive, natural convection in a cubic enclosure subject to opposing and horizontal gradients of heat and solute. The flow is driven by buoyancy forces due to temperature and solutal gradients. Constant temperature and concentration are imposed along the two vertical side walls of the cubic enclosure, while the remaining walls are impermeable and adiabatic. The numerical simulations presented here span a wide range of thermal Rayleigh number (10.0<Ra<2×105), buoyancy ratio (−2.0<N<0) and Lewis number (0.1<Le<150) to identify the different flow patterns and bifurcations. Nusselt and Sherwood numbers are presented as functions of the governing parameters. Most of the published results approximate the problem as two dimensional. In the present results we indicate that the double diffusive flow in enclosures with opposing buoyancy forces is strictly three dimensional for a certain range of parameters.

Double diffusive convection in a cubic enclosure with opposing temperature and concentration gradients

http://hmf.enseeiht.fr/travaux/projnum/sites/default/files/users/lfounini/publication.pdf

Oscillatory double-diffusive convection in a rectangular enclosure with combined horizontal temperature and concentration gradients

Hydromagnetic double-diffusive convection in a rectangular enclosure with opposing temperature and concentration gradients

The problem of unsteady, laminar double-diffusive convective e ow of a binary gas mixture in a rectangular enclosure e lled with a uniform porous medium is considered. A temperature-dependent heat source or sink is assumed to exist within the enclosure boundaries. Transverse cooperating gradients of heat and mass are applied on the two opposing vertical walls of the enclosure while the other two horizontal walls are adiabatic and impermeable to mass transfer. A numerical solution based on the e nite-difference methodology is obtained. Representative results illustrating the effects of the inverse Darcy number, the heat generation or absorption coefe cient, and the buoyancy ratio on the contour maps of the streamline, temperature, and concentration as well as the proe les of velocity, temperature, and concentration at the midsection of the enclosure are reported. In addition, results for the average Nusselt and Sherwood numbers are presented in tabulated form and discussed for various parametric conditions.

/pdf/double-diffusive-convection-in-a-porous-enclosure-with-5aq0gfsaaq.pdf

Jin Wook Lee

Papers

Double-diffusive convection in a rectangle with opposing horizontal temperature and concentration gradients

Double-diffusive convection in a rectangle with cooperating horizontal gradients of temperature and concentration

Time-dependent double diffusion in a stably stratified fluid under lateral heating

Double diffusive convection in a cavity under a vertical solutal gradient and a horizontal temperature gradient