Abstract
In this paper, natural convection in an enclosure which two parallel heated plates are included is investigated experimentally. In the area of between cooled ceiling and heated surface, vortex motion arises when the ascending flow from the upper plates and the accompanying flow to the rising flow from lower area are interfered. Heat transfer around heated surface is enhanced by the vortex motion. In the other areas, the flow is circulated along the heated surface, and average Nusselt number is proportional to modified Rayleigh number at the power in general.
