Calculation Method of the Optimum Configurations of the Extended Surfaces with Simultaneous Conductive, Convective and Radiative Heat Transfer in Heat Exchanger

Abstract

A simultaneous conductive, convective and radiative heat transfer in the extended surface systems of longitudinally finned cylinders and circumferentially finned cylinders is treated analytically, by taking the radiative interaction into consideration. A procedure to determine the optimum configurations of extended surfaces is examined for the various kinds of combinations of six heat transfer parameters from the viewpoint of saving fin material. It is found that if the radiative interaction is not taken into consideration, wrong results are included. Instead of using the complex optimization algorithm, a graphical expression is adopted to show the numerical coefficients and indices in the formulas which give the optimum dimensionless fin height and the minimum fin volume.