Water Droplet Boiling on Hot, Non-Porous Ceramic Surfaces

In this study, an experimental research is conducted, analyzing the behavior of small water droplets (from 10 to 50 :l) gentlydeposited (the Weber number is less than 13) on hot, non-porous, ceramic surfaces. In particular, the conditions whichdetermine the onset of nucleate boiling are emphasized, and the solid surface cooling is monitored via infrared thermography.The results, mainly concerning the evaporation time of the droplets and the solid surface transient temperature distribution,provide some insight into the mechanisms of dropwise evaporative cooling in presence of nucleate boiling. The non-intrusive method of infrared thermography is also used to study the peculiar thermal behavior of industrial ceramic surfaces subjected to high heating fluxes. Dropwise evaporation under boiling conditions is showed to be an effective method to cool down even non-uniform-temperature ceramic tiles.