Interfacial shear modeling and flow predictions for internal flows of pure vapor experiencing film condensation

Internal flow of pure vapor experiencing film condensation on the walls of a straight horizontal duct is studied. The commonly occurring annular case of turbulent (or laminar) vapor flow in the core and laminar flow of the liquid condensate—with or without waves on the interface—is emphasized. We propose and implement a new methodology which models interfacial shear with the help of first-principles based theory, computations, and reliable experimental data on hear transfer rates. Other details of the flow are predicted with the help of this model. These predictions are shown to be in agreement with relevant experimental data. Correlations for film thickness, heat transfer rats, and pressure drops are given