Second law based optimization of free convection film-wise condensation on a horizontal tube

This study uses the entropy generation minimization (EGM) method to optimize a saturated vapor flowing slowly onto and condensed on an isothermal horizontal tube. The result shows that the optimal group Rayleigh parameter exists over the parametric range investigated for horizontal tube at which the entropy generated at a minimum rate. The minimum entropy generation number in condensation heat transfer for optimal diameter, DOPT of tube is expressed in terms of the group Brinkman parameter (Br/ψ). The result provides an immediate estimate of the relative increase in irreversibility associated with using a tube of diameter D ≠ DOPT.