Ergodic simulation of droplet growth during dropwise condensation

Abstract

Coalescence between droplets is responsible for the high heat transfer in dropwise condensation due to smaller droplets repeatedly growing at the exposed area left by merging droplets. In order to comprehend the dynamic process of droplet growth by monitoring each coalescence event during dropwise condensation, an effective local search method based on detection of droplet boundaries was proposed in this paper. This method complies with the dynamic criterion of droplet growth and exhibits ergodic advantage. The present simulation is completely independent of the number of droplets over the whole surface. Therefore, computational time can be significantly reduced. The proposed local search method is validated by a good agreement between the droplet size distribution from experiments and simulation. The present simulation provides an effective approach to more accurately predict the nucleation site density by comparing the measurable quantities (sliding frequency, droplet size distribution and heat transfer coefficient) from both experiments and simulations in future studies.