ABSTRACT
Many physically interesting phenomena in industrial processes and nature involve flow problems with interfaces or fronts. Examples of such phenomena include the casting or mold filling processes, the dendritic solidification and the crystal growth, etc. These phenomena consist of free surface flows and free interface flows. In the free surface flows which describe the interaction between a fluid and air, it is often that the flow equations are solved only for the fluid and zero traction is assumed on the interface. If we formulate them by true two-fluid flow model, we can also regard them as the free interface flow problems. Anyway, in these problems the surface tension effect also plays a fundamental role. It is presented at the fluid-fluid interface for immiscible media.
