Free Convection in Open-Ended Rectangular Cavities-Inclination Dependence

Abstract

Air pressure was employed as the variable to distinguish between the radiative, conductive and free convective components of the heat leak between the isothermal parallel plates of a rectangular cell. A steady-state temperature difference existed between the isothermal parallel plates. The radiative and, to a large extent, the gaseous conductive components were independent of cell inclination. However, for the chosen cell geometry (plates with inclined dimension 15 cm × channel length 12 cm × separation 2 cm) the mean slope of the convective component versus the logarithm of the air pressure exhibited minima at 27° inclination to the horizontal when the plates were at 200°C and 15°C respectively. This phenomenon is due to differing air circulation patterns predominating above and below this inclination.

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