A sharp-interface elliptic two-phase numerical model of laminar film condensation on a horizontal tube

A complete two-phase numerical model of film condensation from a pure vapour that is based on the two-dimensional elliptic governing equations is presented. The model predicts the full viscous flow and heat and mass transfer for the vapour around the tube and in the entire film from the top of the tube to the falling film below the tube. The numerical model uses a dynamically moving computational grid that tracks the phase interface sharply. The model uses an adaptive-grid Eulerian method with a segregated solution method based on a finite volume approach. Fundamental balances of mass, energy, and force are enforced accurately at the phase interface. The model was used to perform a numerical analysis of laminar film condensation from downward flowing vapour over an isothermal horizontal tube. The validity of this new model is demonstrated by comparisons with previous theoretical and experimental studies. New results are presented on the effects of inlet-to-tube temperature difference, upstream Reynolds number and saturation pressure on the condensate film development, the local and average heat transfer coefficients, and the total liquid mass flow rate. (C) 2016 Elsevier Ltd. All rights reserved.