No abstract

No abstract

No abstract

In this paper, a numerical study is performed to investigate the influence of the non?condensable gas type in a vapor mixture of water gas (water vapor?krypton, water vapor?argon, water vapor?air, and water vapor?neon) during the condensation along a vertical pipe with a wall cooled by air-flow. The applied numerical method solves the coupled parabolic governing equations in both gas and liquid phases with the appropriate boundary and interfacial conditions. The equations systems, obtained by using an implicit finite difference method are solved by Thomas algorithm. The numerical results obtained show that the heat and mass transfer is influenced by increasing the molar mass of non?condensable gases. The comparisons of air mass fraction, bulk temperature, local condensate heat transfer coefficient, and average Nusselt number of sensible heat with the literature results and the available experimental data are in good agreement.

This paper deals with a computational study for analysing heat and mass exchanges in the evaporation of a turbulent binary liquid film (water-ethanol and water-methanol) along a vertical tube. The film is in co-current with the dry air and the tube wall is subjected to a uniform heat flux. The effect of gas-liquid phase coupling, variable thermophysical properties and film vaporization are considered in the analysis. The numerical method applied solves the coupled governing equations together with the boundary and interfacial conditions. The algebraic systems of equations obtained are solved using the Thomas algorithm. The results concern the effects of the inlet liquid Reynolds number and inlet film composition on the intensity of heat and mass transfer. In this study, results obtained show that heat transferred through the latent mode is more pronounced when the concentration of volatile components is higher in the liquid mixture .The comparisons of wall temperature and accumulated mass evaporation rate with the literature results are in good agreement.