Conjugate effect of convection and radiation in a circular cavity using water-based graphene nanofluid along with magnetic field

Abstract

The conjugate effect of natural convection and radiation in a two-dimensional circular cavity using graphene-water nanofluid in the presence of a magnetic field has been investigated in this work. The heat source and heat sink are situated in two regions of the circular cavity. Other regions of the enclosure are kept adiabatic. The Galerkin weighted residual of finite element method along with an accurate PDE solver, was utilized to solve the dimensionless non-linear governing partial differential equations. The results are represented in terms of streamline contours, isothermal contours, average Nusselt numbers at the heated surface, and average fluid temperature in the cavity for the buoyancy-driven parameters having Rayleigh number (103≤ Ra ≤106), the radiation parameter (0 ≤ Rd ≤ 1), nanoparticles volume fraction (0 ≤ ϕ ≤ 0.05), and Hartmann number (0 ≤ Ha ≤ 40). The computational outcomes demonstrate that the Rayleigh number, Hartmann number, radiation parameter, and nanoparticles volume fraction significantly changes the temperature distribution and flow movement inside the cavity. Convection heat transfer improves with an increase in the Rayleigh number, the radiation parameter, and the volume fractions of nanoparticles. On the other hand, the average heat transfer rate decreases as the Hartmann number rises. Furthermore, the average heat transfer rate increases by 3.83% when the volume fraction of nanoparticles increases from 0% to 5%.