Evolution of the spatial temperature field during evaporation of a liquid droplet

The present study investigated the phenomenon of heat transfer when a liquid droplet evaporated on a heated structured surface made of black silicon and smooth glass with a graphite coating. Water and volatile dielectric liquid HFE-7100 were used as the working fluids. The temperature fields were studied when shooting with a thermal imager from the top and from the side. A convective flow inside the droplet caused by the Marangoni effect was also investigated. The structures formed inside the heated liquid droplet were analyzed depending on the type of liquid. In particular, for HFE-7100 droplets, the evolution of the flower-shaped convective cells was studied in detail, and the contact line movement velocities were measured during evaporation of microdroplets.