A theoretical model has been developed to investigate the heat transfer phenomena, for steady state free connective film condensation in presence of noncondensable gas where the steam condenses on the vertical surface. The liquid phase heat transfer is modeled as heat conduction across a falling film. The gas-vapor mixture is modeled using diffusion layer theory and heat and mass transfer analogy. An iterative scheme based on heat balance at the liquid/vapor-gas interface has been used for calculating the heat transfer coefficient. The model has been shown to be an useful tool to interpret condensation phenomena, providing theoretical insights into the influence of variables such as pressure, degree of wall subcooling and mass fraction of noncondensable gases. In addition, the model has been validated against experimental data available in literature. The results have also been compared with the correlations developed by Uchida and Dehbi. As film resistance is found negligible during analysis, the interface temperature is assumed as the wall temperature and total heat transfer coefficient is again estimated and compared with the experimental results of Dehbi in the present study.
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