Abstract
A numerical study is performed to examine the effects of nonuniform porosity of a porous medium and thermal dispersion on the natural convection flow and heat transfer of a nanofluid inside a rectangular enclosure containing a fluid and porous layers using a single-phase thermal dispersion model. Copper is considered as nanoparticles and is suspended in a base fluid (water) and the Brinkman-Forchheimer-extended Darcy model is assumed to represent the flow inside the porous layer. The finite volume method with the semi-implicit method for pressure-linked equations (SIMPLE) algorithm is used to solve the dimensionless governing equations, and validation tests of the obtained results are conducted. It is found that the increase in the fluid layer thickness enhances the heat transfer rate at the right wall. Also, an improvement with rate greater than 10% is obtained in the heat transfer rate when the nanoparticle volume fraction is increased to 4%.