SINGLE-PHASE THERMOSIPHON COOLING OF AN ARRAY OF DISCRETE HEAT-SOURCES IN A RECTANGULAR CAVITY

Experiments were performed with FC-77 and water to investigate free convection heat transfer from a 3 x 3 array of flush-mounted, discrete heat sources cooled by an opposing wall in a rectangular enclosure. The effects of the heater location, the enclosure width, the spacing between heaters, and the inclination of the enclosure were studied. For a vertical enclosure, heat transfer was a maximum and a minimum for the bottom and top rows of heated elements, respectively. Heat transfer was not affected by changes in the enclosure aspect ratio. On inclining the enclosure toward a horizontal (heated from below) orientation, the flow became unsteady and three-dimensional, resulting in significantly enhanced heat transfer for the upper element rows.