Heat transfer by natural convection in an annular space partially porous layered and saturated by a nanofluid

The aim of the present study is to investigate the heat transfer by natural convection in an annular space between two vertical concentric cylinders partially filled by a porous medium, with permeable interface, and saturated by a nanofluid (Cu-water). The enclosure is maintained at a constant hot temperature in the inner cylinder, the side wall is maintained at a constant cold temperature while the base walls are impermeable and isolated. The governing system of equations is solved by the use of the finite difference method. The obtained numerical results in terms of streamlines, isotherms and rate of heat transfer expressed by the Nusselt number are presented to show the effect of various parameters such as Rayleigh number, Darcy number and the effect of the interface property. The results of this study shows that the thermal energy augments as the Ra number augments, furthermore, using nanoparticles in the base fluid improves the heat transfer in the active wall.