How to make a smooth interface for multiphase flow with dynamic mesh?
 

http://www.cfd-online.com/Forums/<a ...;0&quot;/></a>Hi all,
I developed a solver which can work with dynamic mesh based on multiphaseInterFoam. The dynamicRefineFvMesh (like interDyMFoam) was used to deal with the mesh motion. I tested the solver on a water-oil-air 3-phase flow. The solver works well but I am not so satisfied with the simulation results, because the interface is not smooth.

I attached a picture of the interface (plotted by alphaair=0.5) to make the question more clearly. The dynamic mesh was refined by the field of alphaoil (0.001-0.999). Some oil droplets distributes under the interface, so the related meshes were refined in the center. The inhomogeneity meshes on the interface result in a rough interface.

I think I did not choose a good mesh motion method. The dynamicRefineFvMesh is not the best choice for my case.
I want to make the mesh refined only for the oil phase, and the oil layer moves along the z-axis. I think it’s better to set a box with refined meshes (oil is inside) and let it move with a constant velocity along the z-axis. Does anybody have idea how to do it?

http://www.cfd-online.com/Forums/<a ...;0&quot;/></a>http://imageshack.us/a/img607/8058/w...rinterface.png



http://imageshack.us/photo/my-images...interface.png/