Numerical Analysis of Natural Convection inside Cubical Cavities Exposed to Diverse Boundary Conditions

Abstract

This paper presents a numerical study of fluid flow and natural convection inside cubical cavities using the finite volume method with second order schemes. Cubical cavities of various sizes with three different thermal configurations were considered, where two opposite vertical walls are isothermal and the other walls are either adiabatic or conducting (with linear temperature variation). The numerical simulations were performed for air and gases with Prandtl number 0.71 under the influence of variable Rayleigh numbers covering the range 10 3 -10 7 . The effects of the three thermal configurations in terms of velocities and temperatures were investigated for both steady and unsteady flow regimes. Additionally, the magnitudes of local and average Nusselt numbers in each direction of the cubical cavity were scrutinized. Using conducting walls, the heat transfer analysis in different directions divulged that the heat flow through the top/bottom walls surpasses 1/3 of the total heat flow of the cubical cavity. Overall, the collection of numerical results demonstrates good agreement when compared with experimental-based and numerical-based publications.