Study Of Capillary Flow In Fan-shaped Interior Corner Under Microgravity

The capillary-driven flow in microgravity is an important basic research topic about the space fluid management technology. To ensure the fluid management devices operate safely and efficiently, it is necessary to deeply understand the characteristics of capillary-driven flow in microgravity. This paper investigates the capillary flow in fan-shaped interior corner under microgravity environment, and studies numerical simulation analysis and the theoretical analysis.The capillary flow in fan-shaped interior corner under microgravity environment is numerically simulated using Surface Evolver software and FLOW-3D software, and it is finally speculated and verified that the Concus-Finn condition of the capillary flow in fan-shaped interior corner is θ1+θ2<90°. Surface Evolver is performed to qualitatively analyze the variation of liquid’s front position, dummy corner angle and meniscus height. Study the influence of different parameters on front position and initial meniscus height by utilizing FLOW-3D satisfying the Concus-Finn condition. The results show that the liquid’s front position increases with increasing coefficient of surface tension, radius and central angles of the container, while decreases with increasing dynamic viscosity, liquid density and contact angle, but the influence of decrease of the contact angle on the arc wall is greater than that on the straight wall, and initial liquid height has no effect on the liquid’s front position. In addition, the research shows that the capillary flow in fan-shaped interior corner is the same as the capillary flow in V-type interior corners, and also has initial meniscus height, it provides an important parameter for the theoretical study of the capillary flow in fan-shaped interior corner.Combining the conclusion of numerical analysis and based on Navier-Stokes equation and the continuity equation of capillary flows in fluid mechanics, the governing equation of capillary driven flows in fan-shaped interior corner satisfying the Concus-Finn condition is established, and the approximate analytical solution is obtained. The function that liquid’s front position is positive proportional to t1/2 is derived. The influence of different parameters on the interior corner flow is studied using a set of typical parameters. The results show that the liquid’s front position decreases with increasing contact angle, while increases with increasing radius of the arc wall. And the influence of decrease of the contact angle on the arc wall is greater than that on the straight wall; these are consistent with the conclusions of numerical simulation.The conclusions of this thesis can be applied in designing tanks and choosing suitable solution in the space fluid management.