Numerical solutions for thermosolutal convection in a vertical concentric cavity partly filled with a porous medium are presented in this paper. The cavity is subject to pre-selected horizontal temperature and concentration gradients. The general Brinkman-Forchheimer-extended Darcy model is adopted to formulate the fluid flow through the porous matrix in the cavity. The effects of the controlling parameters on the flow patterns and heat and mass transfer behavior are thoroughly documented. Different flow structures are produced in the course of the computations, which respond to the geometric parameters, fluid nature, thermofluid dynamic parameters and porous matrix characteristics. The collection of numerical results elucidates that the double diffusion zone varies and, besides it is strongly dependent on the coupling between the Prandtl and Lewis numbers. Moreover, the variations of the Sherwood number show the presence of an extended range of double diffusion phenomena within the conditions pertinent to Darcian flow at Da=10−5. It has been discovered that a partly porous annular cavity is more efficient than a fully porous annular cavity. This aspect may have a beneficial impact on engineering applications in the areas of filtration and thermal insulation.

The present study analyzes numerically the mixed thermosolutal convection in a vertical partly porous annular cavity. The fluid motion in the porous matrix is described by the generalized Darcy-Brinkman-Forchheimer model. The results show that the composite porous layer tends to improve the heat transfer and moderately reduce the transfer of aqueous solution compared to the case of a homogeneous porous partition. This conclusion is valid for all characteristic values (Da, ) or the flow modes set up in the porous matrix.

This paper addresses the effect of thermosolutal convection in the formation of defects in directionally solidified alloys. The numerical model is based on a bi-dimensional solution consisting of an implicit time integration scheme to couple thermal and solutal fields, which is supported by a finite volume numerical modeling technique. In this article, the macrosegregation phenomenon under a static magnetic field effect is analyzed numerically by a computer code developed and validated with experimental data. The numerically obtained results have been widely discussed in dependence of the characteristic parameters of the studied problem.

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Numerical computation is achieved in an axisymmetric configuration to analyze the magnetic field effect on thermosolutal convection during vertical solidification of a binary alloy. The bath is exposed to a uniform temperature profile in unsteady state. During the growth three regions appear: liquid, mushy and solid zones. The mushy zone is assimilated to porous medium. A mathematical model of heat, momentum and solute transfer has been developed in primitive variables (pressure-velocity). A single domain approach (enthalpy method) is used to build the equations system. In this context, a computer code has been developed and validated with previous studies. The results in term of stream function and solute concentration show the strong effect of the magnetic field on the fluid flow and on the solutal stratification. The effects of magnetic field and melt convection intensity were demonstrated. The main results show that the quality of highly doped binary alloy crystals can be improved when the growth process occurs at low pulling rates and under a magnetic field.