Static profiles of capillary surfaces in the annular space between two coaxial cones under microgravity.

In space, surface tension plays an important role and liquid behaviour is much different from that on the ground. The static capillary surfaces in the annular space between two coaxial cones under microgravity are studied in this paper. Theoretical expressions of the capillary surfaces are derived and a procedure is developed to predict the capillary surfaces based on the expressions. By considering various liquid contact angles, liquid volumes, and container geometries, numerical simulation with the volume of fluid method is carried out and microgravity experiments in Beijing Drop Tower are performed. The numerical and experimental results are in good agreement with theoretical predictions. Furthermore, capillary surfaces in an annulus with constant cross-section and in a spherical tank with a central column are also discussed. z ¯ 3 will decrease obviously with the increase of the liquid contact angle. The theoretical models and findings will be great helpful for liquid management in space and the evaluation of propellant residue. [ABSTRACT FROM AUTHOR]