HEAT-TRANSFER IN SQUARE CAVITIES WITH PARTIALLY ACTIVE VERTICAL WALLS

Natural convection of air in square cavities with half-active and half-insulated vertical walls is numerically investigated for Rayleigh numbers of 103-107. This problem is related to applications in solar collection and cooling of electronic components. Five different relative positions of the active zones are considered. While circulation depends strongly on the total exit length downstream of the active zones, heat transfer depends less on this parameter. Significant conduction effects occur even at Rayleigh number of 105. Expressions for average Nusselt number in the five situations and hints on how to generalize heat transfer results to intermediate cases are given.