THE ROLE OF SURFACE-TENSION FOR 2-PHASE HEAT AND MASS-TRANSFER IN THE ABSENCE OF GRAVITY

Surface tension is a very important property at the interface of two-phase systems, and it strongly influences heat and mass transfer. This becomes even more evident in the absence of earth gravity, when buoyancy is strongly reduced and transport processes are determined by the properties at the interface alone. This article discusses various effects occurring at the interface, such as thermocapillary and capillary pressure flow, evaporation and condensation, and coalescence mechanisms. These effects help to explain the independence of boiling heat transfer from gravity, as observed in our microgravity experiments.