ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
USE OF A GAS MIXTURE FOR EXPERIMENTAL MODELING OF MIXED FREE AND FORCED CONVECTION IN ENCLOSURES
Abstract
Experimental study of heat transfer coefficients in air-filled enclosures with mixed free and forced convection using scale models requires obtaining similarity for Reynolds, Grashof and Prandtl numbers between the model and its prototype. In this paper, the theoretical basis for finding gas mixtures which have Prandtl numbers similar to that of air and will meet Reynolds and Grashof number requirements is presented. The best "economical" gas mixture found was a combination of Argon and refrigerant C-318. Experiments concerning suitability were performed. The mixture was shown to be stable in the temperature range considered. The ability of this mixture to produce similarity between model and prototype is compared to what can be obtained with refrigerants previously used to study these heat transfer problems in 1:5 length scale models.