Investigation of local heat fluxes in the contact line area during the growth of a single vapor bubble under microgravity conditions

Abstract

The present work is devoted to the study of heat fluxes from a heating surface into a liquid during single vapor bubble growth. The experiment was conducted as part of the RUBI (Reference mUltiscale Boiling Investigation) boiling project implemented on the International Space Station between 2019 and 2021. Since microgravity increases the spatial and temporal resolution of the problem, this made it possible to study in detail the processes of heat and mass transfer in the area of a three-phase contact line. The paper presents a developed algorithm for determining heat fluxes and the amount of heat transferred from various zones at different experimental parameters: from the contact line area, from the centre under the bubble and from the liquid-vapor interface. In particular, it is shown that it is in the area of the contact line that the maxima of heat fluxes are observed and that evaporation from this area makes a significant contribution to the growth of the bubble (about 50%).