Synchronized Material Parameter Changes Across Different Domains in CFX 2019R2

[1805611570]

I am using ANSYS CFX 2019R2. I have created two adjacent domains, one of which is a porous domain (containing two phases, one solid and one gas), and the other is a fluid domain (containing two phases, both of which are fluids). The two domains are adjacent and share an interface. Why is it that when I change the material in one domain, the other domain also undergoes the same change? Has anyone encountered a similar issue before? How should this be resolved?

[rfblumen]

This behavior is intended.  If there are two domains that share a common interface which allows flow to pass between the domains, both domains must have the same fluids and also the same turbulence model.  If you do not prescribe the same fluids and/or turbulence model, CFX will change the settings in the domains such that the domain physics are consistent.  This is referred to as "Constant Domain Physics".  It helps eliminate set up errors that can later lead to solver failure.

If, in your case, you have Fluid A and Fluid B in one domain and Fluid C and Fluid D inthe adjacent domain, then both domains need to contain Fluid A, Fluid B, Fluid C and Fluid D.

The exception to the above is if the two fluid domains are separated by a wall and cannot mix (e.g. heat exchanger).  In this case, this default behavior may be turned off.  In CFX-Pre, in the tree outline, go under Case Options->General and check the box "Enable Beta Features".  This will expose another check box, "Constant Domain Physics".  Uncheck this box and hit OK.  This will allow for different fluid domains to have different fluids and turbulence models.