Natural convection study in cylindrical annulus through OpenFOAM

The current research employs numerical methods to analyze the natural convection Newtonian fluid in a horizontal concentric cylindrical annulus with constant temperature in a steady-state, two-dimensional scenario. The hot and cold temperatures are assigned to the inner and outer surfaces, respectively. The OpenFOAM software is utilized for numerical simulations, where the conservation laws of mass, momentum, and energy are discretized using a finite volume approach to solve the resulting system of equations. The investigation focuses on examining the influence of different Rayleigh numbers (10² ≤ Ra ≤ 10⁶) at Prandtl number Pr = 10, on the heat and fluid flows. The impacts of Ra numbers on the isotherm, stream functions, vorticity, and enstrophy are emphasized. Finally, the local Nusselt number is calculated and examined for heat transfer. The results suggest that as the Ra number increases, the local Nusselt number increases, which signifies an enhancement in the heat transfer rate.