Quenching experiments inside 6.0 mm tube at reduced gravity

This paper addresses the experimental results of quenching in tubes under microgravity conditions. The objective of the experiment is to obtain quantitative data and observations of the rewetting phenomenon under low gravity level and compare results with the equivalent terrestrial gravity ones. Test tube is made of Pyrex with 6.0 mm in diameter. Tests are performed with FC-72, a fluorinert liquid, flowing inside a vertical test section and upward liquid flow. Measurements included outer wall temperatures along the flow channel, inlet and outlet fluid temperatures, pressure and mass flow-rate. The results show a significant decrease in the quenching velocity at reduced gravity, while the rewetting temperature does not look to be affected by gravity level. The observed flow patterns are inverted annular flow and bubbly flow. The analyses are completed with a detailed high speed video images at normal gravity. These tests reveal the influence of mass flow-rate on the structure of vapour–liquid configuration during the inverted annular flow.