The study on the mechanism of liquid surface in interior corner and the applicability of Surface Evolver

Abstract

The study on the fluid behavior under microgravity condition is of great importance for the investigation of the fluid behavior caused by surface tension, the prediction and control of the liquid location at microgravity, the fluid management in space, etc. In this study, we analyze the relationship between the contact angle and the direction of the contact line in interior corner of container, and compare it with the Concus-Finn theory. The mechanism of mutual correlation among the direction of contact line, the contact angle and the geometric shape of container, and the physical meaning of relevant theory by Concus and Finn etc. are also analyzed. By comparing the theoretical results with the numerical results calculated by Surface Evolver, we find that the Surface Evolver program can predict the contact line and the liquid surface in interior corner with angle smaller than 180°, simply by the automatically partitioned grid. However, when the angle of the interior corner is larger than 180°, the results given by Surface Evolver can have a remarkable error with the automatically partitioned grid. In order to reduce the error, it is necessary to manually partition the surface to reduce the singularity of grid. And the results from Surface Evolver should be tested quantitatively at the interior corners for complicated containers. The theoretical analysis and the numerical results calculated by Surface Evolver in this study will be helpful for understanding the characteristics and mechanism of liquid surface in interior corner, choosing the applicable parameters for Surface Evolver program, and the future study on the behavior of liquid in interior corner, especially under microgravity condition.