Boiling heat transfer and two-phase flow under microgravity conditions

Modelling of two-phase flow patterns and flow regime transistions during quenching processes in microgravity is an essential step in the development of space-based nuclear reactors, or nuclear propelled space vehicles. To investigate these phenomena, a compact experimental test platform was designed and constructed. It consists of a positive displacement pump which forces freon-113 through a heated quartz tube. The vapour is then condensed and returned to the pump. Thermocouples placed along the length of the quartz tube record the progress of the quench front and indicate heat transfer characteristics, while various photographic equipment record the flow pattern. Preliminary ground testing of the apparatus provides reference data, and microgravity tests aboard a NASA KC-135 aircraft will be performed in June 1990. (6 refs., 5 figs.)