Impact of various factors on MHD free convection inside a half-wavy circular enclosure with a centered hot square at the bottom wall filled with CNT/water nanofluid

Recent years have seen an increase in the usage of two-phase models in numerical studies of nanofluids since they allow for a more thorough understanding of heat transport in nanofluids. The present research paper uses a two-phase mixture model to investigate the impact of various factors on heat transfer inside a half-wavy circular enclosure with a centered hot square at the bottom wall filled with CNT/water nanofluid. The numerical simulations of the two-phase mixture model are carried out for the free convection of the nanofluid with volume fractions from 0 to 8%. The flow and heat transfer are investigated at various Rayleigh numbers, Hartman numbers, geometrical parameter N (top wall waviness) and three cases for the dimensions of the bottom square. The results demonstrate that for low Rayleigh numbers, the isotherms were consistent and parallel to the corrugated walls of the cavity due to weak buoyancy forces. However, increasing Rayleigh numbers gave rise to buoyancy forces that contribute to transforming the nanofluid flow into an irregular flow, distorting the isotherms and consequently improving the average Nusselt number. In the existence of magnetic forces, the flow velocity decreases with a significant change in the isotherms pattern. Regarding the geometric effects of the cavity, it is clear from this study's outcomes that the undulation number N and the hot square shape significantly affect the flow and heat transfer strength and the system's irreversibility, thus making them suitable controlling parameters.