Cryogenic Line Quench Experiment In Microgravity

This experiment was designed to provide a visual understanding of the nature of saturated liquid nitrogen flow boiling in a microgravity environment. This was undertaken by obtaining visual records of the flow patterns on film, and qualitatively analyzing them to form a definitive picture of the flow. An experimental apparatus was designed and built to obtain these visual records in microgravity. Liquid nitrogen was supplied from a dewar to an accumulator, from which it was then delivered to a test section. The accumulator was home-built and made of stainless steel. It contained a metal bellows vessel within it. Gaseous helium was supplied to the accumulator to provide the driving pressure. The test section was a 36 inch long, 1/2 inch O.D. quartz tube. Film recordings of the flow patterns were made with a movie camera at various film speeds, with the camera being positioned at different axial locations along the quartz test section. This experiment provided a flow pattern description of the transfer line chilldown and quench process for saturated liquid nitrogen in microgravity, and generated a visual data-base that will support other similar experiments in the future.