Free Convection of Al2O3 and TiO2 Nanofluids in Enclosure with Two Models of Thermal Conductivity

This paper presents a numerical study of natural convection of nanofluids contained in horizontal cylindrical annular enclosure filled with porous media and subjected to uniform heat flux along the inner cylinder wall. Governing parameters of the problem under study are the modified Rayleigh number Ra (10 ≤Ra* ≤ 500) and the solid volume fraction of nanoparticles (0