capillary dominated transport processes in porous media
To provide gas free delivery of propellant at all times, special precautions have to be taken in spacecraft tank applications. Propellant management devices (PMDs) are designed to i) ensure a constant connection between propellant and tank outlet (communication type) or ii) confine the propellant at a designated location (control type).
As shown in Fig.1  (slightly modified) some forms of PMDs feature porous structures (metal screens) which are passive surface tension devices and prevent gas from entering the gallery due to their bubble point. This project aims to investigate the properties of various porous structures from a fluid mechanic point of view, to find a future successor, especially for cryogenic liquids, to substitute the metal screens used today. One of these properties is the ability of the medium to allow wicking of a fluid into its pores. This process is driven by the capillary force, whereas a viscous flow resistance is restraining it.
 P.Behruzi, G.Netter; Concept analysis of PMD designs for future upper stages; 54th Int. Astronautical Congress, Bremen; 2003.