Evaluation of Correlations for Mixed Convective Heat Transfer in a Porous Vertical Cylindrical Annulus

Abstract

This paper presents a numerical investigation of mixed convection heat transfer in vertical packed annulus with air as the working fluid . The inner cylinder is at constant temperature and the outer cylinder is insulated . The flow in the packed annulus is governed by the usual Darcy model . The analyses were carried out in the range of 10 < Ra* < 100 , 1 < Pe < 10 and 0.2 < A < 1 . The effect of each parameter on Nusselt number was explained and shown that it is increased as (Ra*) increased and (A) increased . The best analysis correlation obtained for average Nusselt number was as follows :

Keywords

Heat Transfer