| Steam filmwise condensation is widely used in industries because of its high heat transfer efficiency, such as heat exchanger in refrigeration cycle, passive containment cooling system in nuclear reactor, condenser in power plant, and so on. The liquid film can’t keep smooth in practical application, it is significant to further study wave evolution and heat transfer characteristics of wavy-laminar condensate film.The two-dimensional numerical model for Fluorocarbon Vapor wavy-laminar film condensation on vertical isothermal surface is developed. First, the liquid boundary layer equations for conservation of mass, momentum, and energy are transformed to a new coordinate system, in which the grid is orthogonal. And then apply the finite control volume method to disperse the partial differential equations. Due to the velocity-pressure coupling, the revised SIMPLER algorithm and staggered mesh are used to solve the mathematical model. Discrete equations are calculated by TDMA method. Finally, the flow-field variables distribution are obtained by programming with Fortran Language.A single-frequency forcing perturbation is added continually to film surface, and the wavy flow appears only when the perturbation is amplified. The result shows that whether the response of the condensate film to amplify or damp the disturbance is related to the position of the imposed perturbation. Besides, the wavy amplitude of the liquid film is independent of the perturbation location after the perturbation was amplified. The numerical model captures the evolution of the condensate film wavy interface as it transforms from a smooth surface to the one with small amplitude sinusoidal waves, and eventually to the one with large amplitude noNavier-Stokesinusoidal waves. The local heat transfer coefficients are found to be approximately 40 to 50 percent greater than predicted by the Nusselt smooth film model, as a result of the combined effect of time-averaged film thinning and enhanced convection in the film. |
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