Create the fluid and solid domains in the usual way. If you are solving a rotating problem, your fluid domain should be set up as a rotating domain, while the solid domain should be stationary. Do not create any wall boundary conditions on these surfaces. Create fluid-solid domain interfaces in the usual way. Once you have created the domain interface, you will see that CFX-Pre has automatically created some boundary conditions for the fluid and the solid side. You can then edit the fluid side boundary condition and set a wall velocity, a rotating wall, or leave the walls as stationary as required. A stationary wall is always stationary with respect the local domain.