To study the behavior of capillary surfaces and flow characteristic is very essential for Space Fluid Management, material preparation and many other industries. Under microgravity, the degree of freedom of fluids increases due to lose gravity, which becomes harder to storage, control and transport them. The only thing we can do is how to use adhesion, cohesion and surface tension to achieve fluid management. The study of flow characteristic and interfacial behavior of fluids in interior corners and between parallel plates provides important instruction significance in Space Fluid Management.

In this thesis, we studied the capillary surfaces of liquids in ideal sharp interior corner, rounded interior corner and reflex interior corner with a reflex angle. Also, we analyzed capillary rise of liquid between parallel plates and studied the flow characteristic in open capillary channels with parallel plates.

Theoretical analysis and numerical simulation are performed to research capillary surfaces of liquid drops in rounded interior corners. Comparing with sharp corners, there are some different characteristics of behaviors of capillary surfaces in rounded corners. The behaviors of capillary surfaces in rounded corners are depend on not only contact angle θ and the degree of interior corners 2α, but also the radius of rounded corners r and the volume of liquid drops V, which are dramatically different in sharp corners.

Theoretical analysis and numerical simulation are also performed to research capillary surfaces of liquid drops in reflex interior corners. Some new phenomena were found during simulation. There is a system with a liquid drop and two reflex interiors which are symmetrical distribution in a special way. If contact angle and the half of degree of interior corners satisfy θ+α<π, the liquid drop can be fixed in the center of system. Otherwise, If contact angle and the half of degree of interior corners satisfy θ+α>π, the liquid drop will move to either side of two sides of system. The bigger the sum of contact angle and the half of degree of interior corners is, the greater is the degree of bias to one side.

Theoretical analysis and numerical simulation are still performed to research capillary rise of liquid between parallel plates. Liquid rises automatically due to capillary force between parallel plates. At the beginning of capillary rise, the height of capillary rise is proportional to the square of time, which is the same with capillary rise in cylindrical tubes and porous media. After capillary rise for a very long time, capillary flow between parallel plates and in cylindrical tubes can be assumed as Poiseuille flow, which can lead that the height of capillary rise is proportional to the square root of time.

To study the open capillary channel flow, we use numerical simulation and obtain much information about flow. There is a phenomenon which is inconsistent with other people’s conclusion. We found that the volume of the ingested bubbles increases when the flow rate is increased in various supercritical flow rates. We prove that this phenomenon is reasonable theoretically. Furthermore, we perform experiment under normal gravity environment for the first time and again verify that phenomenon is reasonable, which illustrates our conclusion is correct and unbreakable.