Magneto-thermo-gravitational Rayleigh–Bénard convection of an electro-conductive micropolar fluid in a square enclosure: Finite volume computation.

AbstractThis article presents both a theoretical and a numerical analysis of thermo-gravitational magnetic convection in electro-conductive Eringen micropolar fluids in a two-dimensional enclosure. The computational regime is bound with cold top, hot bottoms, and adiabatic side walls. The governing equations were transformed via scaled variables into dimensionless partial differential equations. A Finite volume method (FVM) is used to get a solution of the computational regime. Validation of the FVM solutions is included for non-magnetic special case from the literature. Streamline contours, isotherm contours, iso-microrotation contours (lines of constant angular velocity) and local Nusselt number at the left hot wall is depicted graphically for the impact of Hartmann (magnetic) number (<italic>Ha</italic>), Prandtl number (<italic>Pr</italic>), micropolar parameter (<italic>K</italic>) and Rayleigh number (<italic>Ra</italic>). A significant modification in internal circulation and micro-rotation in addition to temperature distribution is observed with increasing vortex viscosity parameter. Significant warping of isotherms is induced with stronger magnetic field and the mushroom-shaped core structure encountered at weak magnetic field transitions to a sigmoidal topology. [ABSTRACT FROM AUTHOR]