Combined effect of rotation and magnetic field on Rayleigh-Bénard convection of a nanofluid layer in porous medium

Abstract

To study the interdependent influence of rotation and magnetic field while acting simultaneously and keeping in mind applications of flow through porous medium in geophysics, especially in the study of earth's core and the presence of nano particles therein; the hydromagnetic stability of rotating nanofluid layer in porous medium is considered. Darcy-Model is incorporated for free-free boundaries. Method of superposition of basic modes and single term Galerkin approximation is used to get the eigen value equation. The mode of instability occurs through oscillatory motions instead of stationary convection. Numerical analysis for water based nanofluids with Cu and Ag nanoparticles is carried out using the software Mathematica. Ag-water nanofluid exhibits higher stability than Cu-water nanofluid in the presence of rotation and magnetic field in porous medium. Rotation parameter and magnetic field parameter are found to inhibit the onset of thermal convection while permeability assists the same.