Thermal dispersion and its impact on the onset of convective instability in Prats flow through porous media

This study investigates the effect of thermal dispersion on the onset of convective thermal instability in a fluid-saturated porous medium. The analysis focuses on a horizontal throughflow within a layer bounded by two uniformly heated horizontal rigid impermeable walls. These walls are maintained at a constant temperature gradient, which induces buoyancy and triggers convection. By incorporating thermal dispersion, the study examines its influence on natural convective instability arising from thermal buoyancy. The paper introduces a novel perspective on the role of thermal dispersion in convective instability. The inclusion of Prats flow reveals that instability can manifest in both monotonic and oscillatory modes, with convection sometimes initiating in oscillatory modes.