Optimized use of baffles for reduced natural convection heat transfer from a horizontal cylinder

The problem of laminar natural convection from a horizontal cylinder with one or more low conductivity fins (baffles) on its outer surface was investigated numerically. The aim was to optimize the number, size, and location of the baffle(s) for maximum natural convection heat convection. i.e.. Nusselt number, over a wide range of Rayleigh number. The percentage reduction in heat transfer per baffle(s) unit length "cost-efficiency" was also studied. Changes in the thermodynamic efficiency was studied by calculating the entropy generation associated with each baffle configuration. It was found that the proper placement of a single or dual baffles has a significant effect on the heat transfer and entropy generatuion reduction. The optimal single and dual baffle locations is reported for different values of Rayleigh number and baffle height. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.