抄録
We investigated the heat transfer during tube quenching for developing an on-orbit cryogenic fluid management system. This paper describes the experimental results of tube quenching for two flow directions (up flow and downflow) under terrestrial conditions. Liquid nitrogen (LN2) is used as the test fluid, and it is injected into a transparent heated tube at a mass velocity of 100-600 kg/m2s. The tube is made of pyrex glass, and it has an inner diameter of 13.6 mm and a wall thickness of 1.2 mm. The thermal data reveals that the quenching time during which the inner wall temperature became equal to the LN2 boiling temperature (77.3 K) under up flow condition is less than that under downflow condition. The flow visualization data reveals the existence of a filamentary flow only under the downflow condition, and this flow pattern leads to a decrease in the cooling rate of the tube wall.
