Influence of Aperture Height and Width on Interzonal Natural Convection in a Full-Scale Air-Filled Enclosure

The topic of this paper is the influence of aperture height and width on interzonal high Rayleigh number, natural convection heat transfer. Experiments were conducted in an 8 ft. air-filled cube divided into two zones by a vertical partition which was centered between a constant flux hot wall and an isothermal cold wall. The partition was configured to form doorway-like apertures. The aperture height relative to test cell height range from 1/8 to 1 and the aperture width relative to test cell width ranged from 0.009 to 1. The zone-to-zone temperature difference and the overall Nusselt number were determined experimentally, and correlated with the overall Rayleigh number, aperture, and enclosure geometry, using a series resistance model for the enclosure. A turbulent boundary layer resistance was used to represent the hot and cold boundary layer flow, while an orifice resistance was used to represent the aperture flow. For flux Rayleigh numbers between 5*10¹¹ and 5*10¹², the enclosure Nusselt numbers ranged between 15 and 165, with a strong dependence on aperture height.