Effect of Corner Roundedness on Capillary Flow of Liquid Propellants in Microgravity

Abstract

The theory of interior corner flow driven by surface tension provides an important support for design of liquid management devices in space. The flow rate, velocity, and liquid position are important factors to determine liquid management efficiency. In practice, due to machining precision or aiming to enhance the mechanical strength, the interior corner is often imperfect with a certain degree of roundedness. In this paper, the influence of corner roundedness on liquid flow characteristics is quantitatively analyzed by combining theoretical and experimental analysis. The results show that with a fixed corner roundedness, the height of liquid is always proportional to the square root of time. The velocity of capillary flow also decreases with the increase of corner roundedness. The present theoretical model is validated by the microgravity experiments based on magnetic compensation. Furthermore, the model is applied to simulate the capillary flow of liquid hydrogen and liquid oxygen. The variations of flow rate under different conditions are obtained, which provides important basic data for the design of liquid management devices for cryogenic propellant.

Keywords

• surface tension
• interior corners
• capillary driven flow
• roundedness
• magnetic compensation
• cryogenic propellant