Natural convection in square enclosure with an internal isolated horizontal plate

In this paper, the natural convection in an enclosure with an internal isolated horizontal plate was numerically investigated. The fluid filled in the enclosure was air. It has been found that for a fixed plate position, the plate average Nusselt number increases with increase in Rayleigh number, and at a fixed Rayleigh number, there is a certain plate position for which the plate Nusselt number reaches its maximum. The flow pattern was also revealed by smoking technique and the agreement between the predicted streamlines and the flow visualization results is very good.