Simulation of natural convection in a square cavity with micropolar fluid and magnetic fields using FVM

Abstract

This paper investigates the heat and mass transfer characteristics of micropolar nanofluid contained within an enclosure subjected to buoyancy force and magnetic field. The mathematical model is developed using governing equations mass, energy, and momentum to assess the thermal efficiency of micropolar fluid. The objective of this research is to enhance the effectiveness of heat and mass transfer in industrial heat transfer devices and heat recovery systems utilized in engineering processes. The considered numerical study visualizes the magnetic hydrodynamic effect in two-dimensional natural convection heat transfer occurring from a square enclosure. The fluid inside the enclosure travels in a laminar pattern, incompressible and time-dependent. The research deals with micropolar fluid characterized by its Prandtl number (Pr=0.71). The horizontal magnetic field is utilized in the system. To discretize the nonlinear paired dimensionless boundary value problem the computation technique known as Versteeg and Malalasekera Finite Volume Method (FVM) is used.The graphical representation illustrates the influence of crucial control parameters on streamline contours, isotherm contours, and local Nusselt numbers. The convective flow and heat transfer within the cavity are affected by an elevation in the vortex viscosity parameter. As a result, the streamlines and isotherms are largely invariant to a change in magnetic field orientation. Moreover, it has been found, that the higher Rayleigh numbers may induce vortices and eddies, creating secondary flow structures that enhance heat transfer and also the stronger buoyancy forces, driving more significant fluid motion and convective heat, resulting in more pronounced variations in temperature. Also, the study investigates how the placement of heat sources and the configuration of multiple heat sources impact the system, aiming to provide qualitative recommendations for enhancing cooling system design.