Investigation of oscillatory second-grade fluid flow through porous media under slip and thermal influences

This study presents an analytical investigation of oscillatory magnetohydrodynamic (MHD) flow of an electrically conducting second-grade fluid through a porous medium, incorporating the combined influences of velocity slip, thermal radiation, and a first-order chemical reaction. The governing momentum, energy, and concentration equations are formulated using the Boussinesq approximation and Darcy’s law, assuming laminar, incompressible, and time-dependent flow. Through appropriate similarity transformations, the system is reduced to a set of ordinary differential equations, for which exact solutions for velocity, temperature, and concentration are derived. The results reveal that magnetic field strength and buoyancy forces significantly suppress fluid velocity due to enhanced Lorentz and thermal resistance effects, whereas thermal radiation elevates temperature throughout the channel. Increasing the Schmidt number and reaction rate reduces solute concentration, indicating diminished mass diffusivity. Heat and mass transfer characteristics, quantified through Nusselt and Sherwood numbers, show that higher Prandtl numbers enhance thermal transport, while stronger chemical reactions lower mass transfer rates. The main novelty of this work lies in obtaining closed-form solutions for oscillatory second-grade fluid flow in a porous medium under the simultaneous effects of slip, radiation, and chemical reaction, offering benchmark results and valuable physical insights for applications in heat exchangers, catalytic reactors, polymer processing, and biomedical flow control systems.