Thermal Instability of Chemically Reactive Couple-Stress Ferrofluids in an Anisotropic Brinkman Porous Medium

Abstract

The thermal instability of a chemically reactive couple-stress ferrofluid in an anisotropic Brinkman porous medium is examined in the current work. The fluid is subjected to a tiny perturbation in the study and it is assumed that this perturbation results in a chemical reaction with zero-order energy release. While maintaining a constant temperature at the lower boundary, the system is cooled from the top layer. The Rayleigh number is determined through the application of linear stability analysis and the Galerkin method. Attention is focused on the effect of magnetic, chemical, anisotropic and couple-stress parameters on the onset of ferroconvection in an anisotropic Brinkman porous medium with chemical reaction and anisotropic properties. It is shown that the system is strongly stabilized through the presence of the porous matrix and couple stresses. The mutually antagonistic influence of the thermal and mechanical anisotropic parameters is also validated. Notably, it is substantiated that in the presence of couple stresses, the destabilizing impact of both magnetic stresses and chemical reaction could be effectively controlled. The findings of the problem shed some light on the potential use of ferromagnetic fluids in the effective control of heat transfer mechanisms.