Capillary Phenomena Between Plates from Statics to Dynamics Under Microgravity

Plate type surface tension tanks have been widely used in satellites. Capillary phenomena between plates is an important part of liquid behaviour in space. Capillary phenomena between plates with varying width and distance under microgravity are analyzed in detail in this paper. A second-order differential equation for the meniscus height is derived and it can be solved by using the fourth-order Runge-Kutta method. To ensure the model's accuracy during the entire flow process, the influences of the dynamic angle, the friction force, the convective pressure loss and the liquid meniscus in the reservoir are all considered. For a long time period of flow, the convective pressure loss can be neglected and the equation is simplified. This equation is valid for flows between plates with small varying aspect ratios. Theoretical results are in good agreement with numerical results. Besides, influences of the variation of width or distance of plates are discussed. The flow speed won't vary monotonically as the distance between plates varies parabolically. The optimized flow channel is possible to be obtained based on this equation.