Effect of Chemical Reaction on Heat and Mass Transfer in MHD Rotating Flow of a Couple Stress Fluid through a Porous Medium with Temporal Oscillatory Permeability

Abstract

The present investigation focuses on the analysis of heat and mass transfer characteristics in an unsteady free convective magnetohydrodynamic (MHD) rotating flow of a couple-stress fluid past a vertical porous plate embedded in a porous medium. The study incorporates the effects of time-dependent oscillatory suction and permeability, along with the presence of an internal heat generation source and a first-order homogeneous chemical reaction. The influence of an externally applied transverse magnetic field is also taken into account to examine its role in controlling the flow dynamics. The governing system of highly nonlinear partial differential equations describing the conservation of momentum, energy, and species concentration is formulated under appropriate physical assumptions. These equations are rendered dimensionless using suitable similarity transformations and are subsequently decomposed into steady and oscillatory components to facilitate analytical treatment. The resulting coupled nonlinear differential equations are solved numerically using an efficient numerical scheme. A comprehensive parametric study is carried out to illustrate the effects of key dimensionless parameters, such as the magnetic field parameter, rotation parameter, couple-stress parameter, permeability parameter, heat source parameter, and chemical reaction parameter, on the velocity, temperature, and concentration distributions. The numerical results are presented graphically and discussed in detail to highlight the underlying physical mechanisms governing the flow behaviour. The findings of this study are expected to be useful in understanding complex transport phenomena in engineering and industrial processes involving non-Newtonian fluids, porous media, and MHD applications.