Numerical investigation of dropwise condensation on plain and functional surfaces

Condensation, a natural phase change phenomenon, is extremely significant in a variety of applications, from power generation to electronics cooling. While previous studies have predominantly focused on experimental studies and single droplet simulations, there is a gap in the literature on the comprehensive numerical analysis of dropwise condensation and parameters affecting its performance. By simulating condensing flow on different surfaces and considering major parameters, this study reveals the effect of the steam mass flux and wettability on dropwise condensation. The unique aspect of this study lies in the multiparametric simulations to obtain the entire dropwise condensation cycle, elucidating the dynamic processes. The findings reveal that a higher steam mass flux improves heat transfer, as the droplet departure diameter adversely changes with the steam mass flux. Surfaces with low wettability exhibit substantial improvements in heat transfer (up to a 33% increase in heat transfer coefficient) at high steam mass fluxes compared to highly wettable surfaces. The findings consistently display a beneficial relationship among higher contact angles, decreased departure droplets, and superior heat transfer performance. Furthermore, this work validates the developed numerical model through comparison with experimental results, which provides the reliability of the computational approach in accurately modeling dropwise condensation and predicting and optimizing dropwise condensation behavior for different applications.