Modeling of dropwise condensation on flat surfaces

There are two ways for a vapor to condense on a surface: filmwise condensation (FWC) and dropwise condensation (DWC). The interest in DWC is based on the potential increase of the condensation heat transfer coefficient (HTC) by 6 to 10 times compared to the values measured during filmwise condensation. For this reason, several research groups around the world have tried to promote the dropwise condensation and to describe the underneath mechanisms. Such models describe the phenomena that take place during dropwise condensation: the nucleation of a droplet until its departure, the heat exchanged by the drop during its lifetime and the droplets population on the surface. The present paper aims at presenting some of the models developed in the past years which can be used to describe the DWC process. In particular, similarities and differences between the models are highlighted and their predictions are compared against experimental data measured at the Two-phase Heat Transfer Laboratory of the University of Padova.