Theoretical Study of Dropwise Condensation Heat Transfer: Effect of the Liquid-Solid Surface Free Energy Difference

Dropwise condensation beat transfer depends not only on the condensing conditions, but also on the interfacial phenomena between the condensate and the condensing surface, expressed as the surface free energy difference between the condensate and the condensing surface. A model was developed based on the well-established Rose's model with consideration of the interfacial interaction between the condensate and the condensing surface, and by rebuilding the spacial drop-size distribution into the time domain. Simulation results indicate that the heat transfer coefficient increases as the surface free energy difference increases and the contact angle hysteresis decreases. Larger contact angles and smaller departure diameters result in higher heat transfer coefficients. Simulation results for the selected solid-liquid-vapor system are in good agreement with experimental data, the predictions of Rose's model and experimental data in the literature.