Natural Convection Heat Transfer Between Cylindrical Tube Bundles and a Cubical Enclosure

Abstract

Natural convection heat transfer from a fixed array of four isothermal, heated cylinders to an isothermal, cooled cubical enclosure was experimentally investigated for both a horizontal and vertical position of the array. Included in this study are heat transfer, flow visualization, and temperature profile results for Prandtl numbers in the range of .7 to 3.1 × 104 and Rayleigh numbers, based on gap width, in the range of 6.3 × 105 to 6.9 × 108. Several geometric effects were observed. The vertical configuration convected less heat than the horizontal while a rotation about the vertical axis for each of these configurations had negligible effect on the overall heat transfer. The heat transfer results were correlated and compared with previous enclosure results. The heat transfer correlations fit the data with an average deviation of less than 10 percent.