Modulated Gravity Effects on Chemically Reactive Solutal Convection in Anisotropic Porous Media

Abstract This study presents a weakly non-linear stability analysis to examine the influence of time- periodic modulated gravity on mass transport. A saturated porous layer of Newtonian fluid, confined between two parallel and infinite horizontal plates located at with the upper boundary salted, is considered. The investigation focuses on the effects of vertical, sinusoidal, and time - dependent gravity (g) on the onset of solutal convection in the presence of a chemical reaction. In the considered scenario, the gravitational field comprises a constant component and a time -periodic component introduced externally, simulating oscillations in the fluid - saturated porous medium. Infinitesimal disturbances are expanded in a power series of the modulation amplitude, which is considered to be small. The Ginzburg - Landau equation is derived to evaluate the mass transfer rate. Through this analysis, the dependence of mass transport and linear stability criteria on key parameters like solutal Rayleigh number, Darcy number, Schmidt number, and Damköhler number - is thoroughly explored. The findings suggest that by appropriately tuning the frequency and amplitude of the imposed modulation, mass transport can be effectively controlled.