Abstract
This paper addresses the experimental results of quenching in tubes at microgravity conditions with the objective to gather quantitative data and observations of the rewetting of hot surfaces at microgravity conditions. Test tubes are made of Pyrex with different inner diameters, 2.0, 4.0 and 6.0 mm. Tests are performed with vertical test section and upward fluid flow. The test fluid is FC-72, a fluorinert liquid. Measurements included wall temperatures along the flow channel, inlet and outlet temperatures, pressures and mass flow-rate. The 6.0 mm tube shows a significant decrease in the quenching velocity at reduced gravity, while the rewetting temperature is not affected by gravity level. For the smaller pipe diameters the effect is still present, though less evident. The observed flow patterns are: inverted annular flow and bubbly flow. These tests reveal the influence of mass flow-rate on the structure of vapour-liquid configuration during the inverted annular flow.
