Heat Transfer from an Insulated Cube Using a One-dimensional Approximate Method

Abstract

Heat transfer problems of an insulated regular cubic box or sphere are important in engineering airconditioning and refrigeration systems, for example, refrigerator insulation or a nitrogen tank. This study analyzes the heat transfer characteristics of insulated and bare cubes using a one-dimensional approximate “sector method.” In this method, it is assumed that a small element of the cube is of the shape of a small element of an imaginary sphere with the center of the sphere at the cube's center, and the temperature remains constant in both x and y directions for a small angle. It is found that, in the case of bare cubes, the heat transfer by the “sector method” is better over the plate thermal resistance (PTR) model and very close to the CPSWT model, a combination of the PTR model and square top solid wedge thermal resistance (SSWT) model.