Experimental study of heat transfer by natural convection in a closed cavity: application in a domestic refrigerator

An experiment was carried out using a refrigerator model in which heat is transferred by natural convection between a cold vertical wall and the other walls, which are exposed to heat losses. The air temperature profile in the boundary layers and in the central zone of the empty refrigerator model was investigated. Temperature stratification in the vertical direction was observed with the cold zone at the bottom and warm zone at the top of the cavity. The effects of temperature and the surface area of the cold wall were studied. In order to study the effect of obstacles on temperature profiles, the refrigerator model was filled with 4 blocks of hollow spheres. Temperature profiles in this case were compared with the results with no blocks. The air temperature is lower almost everywhere in the model containing blocks. The presence of the blocks seems to enhance heat transfer particularly near the cold wall. (c) 2004 Elsevier Ltd. All rights reserved.