The Capillary Rise of Liquids in a Metallic Weave: Evaporation Effects

Abstract

Many applications rely on the capillary rise of liquids in porous media. In spacecrafts for example, propellant management devices (PMDs) are used to provide gas free delivery of propellant during all acceleration conditions of the flight. Many PMDs use a metallic weave which, when wetted by the propellant, prevents gas from entering below a critical bubble point pressure. If volatile or cryogenic liquids are used refilling of the weave becomes important as it could dry out and become inoperative. We study the role of evaporation for the capillary rise of different liquids in a dry Dutch Twilled Weave (DTW 200×1400). The Lucas and Washburn model is extended to include evaporation and gravity effects. By comparing the experimental results with the enhanced wicking model we find good qualitative agreement. It is also noted that evaporation may have a major impact on the height gained due to capillary action.