Review of existing research on microgravity boiling and two-phase flow: Future experiments on the international space station

This paper describes research objectives on boiling and two-phase flow under microgravity conditions from both scientific and technological points of view. Existing research for various systems in flow boiling are briefly reviewed and problems indicated for research conducted by available facilities with short microgravity duration. A wide range of experimental subjects that become possible by using different types of test sections is clarified and the validity of long term experiments is emphasized. A first step outline is described for a test loop with interchangeable test sections, such as transparent heated tubes, transparent flat heating surfaces, and narrow channels optimized for individual objectives and restricted by specifications of the facility.