Boiling Two-Phase Flow experiment in microgravity onboard International Space station

A series of systematic experiments was performed using a boiling and two-phase flow loop under the microgravity condition provided by the International Space Station. Based on the understanding of gas-liquid interfacial behaviour and highly reliable data on heat transfer characteristics from this experiment, we clarify the details of elementary processes concerning boiling two-phase flow under the microgravity condition. This experiment also demonstrates a boiling cooling system in space. Through this experiment, we acquired data useful for designing a high-performance and compact thermal control system, aiming to develop it into an innovative space platform. The microgravity experiment was performed from July 2017 to March 2018. The experimental facility worked well, and a lot of data were able to accumulate. Under the certain regime of experimental condition, it was completely different from the behaviour of boiling bubbles on the ground. As a result, heat transfer also showed unique characteristics.