Numerical Modeling of Annular Film Condensation Inside a Miniature Tube

Abstract

This article presents a mathematical formulation of forced-convection condensation of pure fluid and binary mixtures. The efficient of the physical model is in solving the coupled heat and mass transfer equations and in taking into account the variation of the condensate film thickness. The numerical algorithm for the nonlinear governing equations has been iterated and produced excellent convergence behavior. Effects of tube diameter on the condensate film thickness, pressure, local axial velocity, average heat transfer coefficient, and the friction factor are examined. Decreasing the concentration of R134a increases the average heat transfer for condensation of the mixture R123/R134a.