ISSN Online: 2377-424X
ISBN Print: 0-89116-909-1
International Heat Transfer Conference 9
HEAT TRANSFER BY NATURAL CONVECTION FROM A HORIZONTAL CYLINDER EMBEDDED IN A POROUS MEDIUM: THE WALL EFFECT
Abstrakt
Experimental data have been obtained for heat transfer by natural convection from a series of Isothermal heated horizontal cylinders embedded in porous media whose matrices consisted of randomly packed glass spheres. The saturation fluids were water and two grades of silicone oil (10 and 20 centistokes). The range of the dimension ratio d/D, where d and D denote the diameters of the glass spheres and test cylinders, respectively, was from 0.1 to 2. It was found that the wall effect, which here refers to the influence upon the heat transfer coefficient caused by nonuniformity of the porosity near the cylinder wall, diminishes the heat transfer coefficient by an amount that increases with d/D. Previously published correlation equations have been modified by incorporating therein correction factors such that the modified formulas correlate the experimental data considered here with a mean deviation of 11% in both the Darcy and Forchheimer regimes of flow.