Numerical study on capillary flow behavior of perpendicular and parallel vanes in microgravity: Insights into vane configuration selection

Surface-tension tanks are employed for propellant management in spacecraft, which require vane-type propellant management devices for liquid positioning and transport under microgravity conditions. This study numerically investigated the capillary-driven flow of two typical vane configurations—perpendicular and parallel vanes—inside a cylindrical tank using the volume-of-fluid method. The effects of vane type, number, and installation angle on the liquid transport performance were systematically analyzed. The results indicate that parallel vanes facilitate faster liquid transport via uniform capillary gaps and maintain reliability, even under a higher gravity level (10−3g0). Alignment of the gaps with the flow direction ensures an independent and consistent capillary driving force that was unaffected by the vane number or installation angle. In contrast, perpendicular vanes rely on radial corner capillary action, which is dispersed in multivane configurations, slowing transport but enhancing total liquid delivery owing to a greater radial storage space. These findings elucidate the relationship between the vane design and fluid behavior and offer valuable insights for optimizing aerospace surface-tension tanks.