Coupled buoyancy and Marangoni convection in a hybrid nanofluid-filled cylindrical porous annulus with a circular thin baffle

The purpose of the current article is to evaluate the impact of coupled buoyancy and thermocapillary driven convection in a cylindrical porous annulus saturated with Ag/MgO–water hybrid nanofluid along with viscous dissipation effects. The left side wall of the annulus is kept heated, while the right side wall of the annulus is kept cold. The top and bottom limits are supposed to be adiabatic. A thin circular baffle is anchored to the inner cylinder. The primary goal of this research is to look into the effect of baffle size and location on Marangoni convection, thermal behaviour, and flow fields. Here, the effects of viscous dissipation are taken into account. The governing equations are subjected to the finite difference approach, which employs the ADI, SOR, and central differencing schemes. In this work, contour plots and average Nusselt number profiles are used to demonstrate the flow type, temperature behaviour, and thermal variations along the enclosure. The research demonstrates that the size and location of the fin plays a prominent role in influencing fluid flow within the annulus. An improvement in thermal transfer rate is reported for ϕ and for the higher value of Ma considering the viscous dissipation, length and location of the baffle.