Conjugate heat transfer of a finned oval tube part B: Heat transfer behaviors

Conjugate heat transfer in a high-performance finned oval tube heat exchanger element has been calculated for a thermally and hydrodynamically developing three-dimensional laminar flow. The influence of Reynolds number in the range 100-500 and of a fin parameter Fi, the product of the dimensionless fin thickness and its thermal conductivity, on the heat transfer behavior hale Been studied. In part I, the computed velocity field was presented. Here we present the heat transfer behavior, including heat flux on the tube, fin temperatures, fin Nusselt numbers and heat flux distributions, fin efficiencies, Colburn j factor, and apparent friction factor f(app). For the investigated configuration, the ratio of heat transfer on the tube to that on the fin remains under 10%. The fin temperature and fin efficiency depend weakly on Fi.