Cold pressurant gas bubble point experiments for coarse mesh screen channel liquid acquisition devices in liquid nitrogen

Abstract

Screen channel liquid acquisition devices (LADs) will play a crucial role in future deep space travel. It is essential that vapor-free delivery of propellants during in-space transfer is ensured to maximize yield from storage tanks and prevent potential combustion instabilities. The screen channel LAD utilizes a fine screen wire mesh that can separate phases in a low Bond number (i.e. microgravity) environment using surface tension forces. This paper presents cryogenic liquid nitrogen (LN2) screen channel LAD bubble point experiments focused on coarser mesh screens. A total of 14 different screen types are tested across a range of cryogenic liquid temperatures near the screen (70.8 − 80.0 K) and dewar pressures (∼101.3 – 156.5 kPa or ∼0 – 8 psig) for two pressurization schemes (noncondensable gaseous helium and autogenous pressurization with gaseous nitrogen) to examine the effect of pressurant gas type on LAD performance. Cold pressurant gas bubble point test results for coarser meshes shown here agree almost perfectly with historical trends using fine mesh screens. Pressurization with a noncondensable generally leads to higher bubble point due to evaporative cooling at the LAD screen while pressurization with the vapor generally leads to degradation in performance due to condensation of the vapor and subsequent interfacial heating.