Effect of Periodic Heating Conditions on Natural Convection in an Enclosure Filled with Copper-Water Nanofluid

Natural laminar and transient convection in an enclosure filled with Cu-Water based nanofluid, is analyzed numerically. The vertical walls are active by applying periodical heating boundary conditions and those horizontal are adiabatic. The enclosure is filled by a Newtonian and incompressible nanofluid. Calculations were performed for Grashof number (10(3) <= Gr <= 10(6)) and volume fraction of nanoparticles (0 <= phi <= 0.1). The angle of inclination is fixed at 45 degrees. The finite volumes method is used for discretization of the governing partial differential equations and the SIMPLER algorithm for handling the pressure-velocity coupling. We verified the validity of our model by comparing the results of this study with other similar results existing in the literature. The relevant results are presented in terms of isotherms and streamlines graphs and the heat transfer rate is translated in terms of the average Nusselt number along the hot side wall. It is found that the average Nusselt number increases with the increase of the buoyancy parameter (Gr) and nanoparticles concentration (phi). In addition, a comparison between the two cases of periodical heating regarding the flow intensification and heat transfer was done.