[abc197]

Hi, I am working on a problem with countercurrent multiphase flow in an inclined cylinder.(Using air and sand). Sand enters from elevated side in a way that interface line makes 90 degree angle at centre of the circular inlet section. Both air and sand have constant mass flow rates as their respective inlet conditions and other properties.
In figure attached, face 5 is the interface. Sand is below this face and air on above. So far both inner circular face and arc face are disconnected. What more needs to be done here(except meshing,inclination and zone assignement). OR I shouldnt make sand zone at all? If its OK here then how to active those interfaces.