FSI with two different fluid region
 

Hello everyone,

I am trying to model a tank with a diaphragm that separates two different fluid regions (gas and liquid). I am modeling the diagram as a solid region. In the Star ccm+ tutorials, solid stress diaphragm valve modeling is kind of similar to my model but I need help setting up the overset mesh.

- Since I have 2 different fluid regions, should I create an overset region for both of them or do I need only 1 that contains gas, liquid, and solid (diaphragm)?

- In the tutorial, the fluid contains a solid region where the solid region has not been extracted from the liquid region. Should I place my diagram in the model as in the tutorial or should I create an interface between them?