Analysis of MHD Thermosolutal Convection in a Porous Cylindrical Cavity Filled with a Casson Nanofluid, Considering Soret and Dufour Effects

Abstract

The aim of this work is to numerically and theoretically model thermosolute natural convection in porous, isotropic and saturated media filled with Casson nanofluids (aluminum nanoparticles) under the influence of a magnetic field. Calculations were performed for various parameters relevant to our model, namely Casson fluid parameters (between 0.1 and 1), thermal Rayleigh number (between 10 and 100000), Geometric aspect ratio number (between 1 and 3),Buoyancy ratio number (between 1 and 10), Soret and Dufour numbers (between 0.2 and 1.2), conductivity ratios (between 1 and 3) and Hartmann numbers (between 0 and 100). The horizontal walls of the enclosure maintain uniform temperature and concentration, while the side walls are rigid, watertight, and insulated. Casson nanofluid flow occurs in porous layers and is described by the extended Darcy law of Brinkman-Forchheimer. The finite volume method was used to spatially discretize the obtained system of equations. Therefore, we investigated the effect of different parameters on the heat transfer rate and concentration. we observe that heat and mass transfer increases with increasing Casson fluid parameter; this increase is significant for the case of β between 0.1 and 0.4. And it also increases with the increase in the number of thermal conductivity ratios, the number of thrust ratios and with the increase in the thermal Rayleigh number. The latter remain unchanged when the thermal Rayleigh number is below the threshold . In the Opposite, we notice an uneven decrease in the thermosolutal transfer with the increase in the Hartmann Soret and Dufour numbers.

Keywords

• casson nanofluid
• extension of the law of darcy
• mhd thermosolutal convection
• soret and dufour effects