## 36.6. Interface Definition

Domain interfaces are used to connect multiple assemblies together, to model frame change between domains, and to create periodic regions within and between domains. Domain interfaces are automatically generated based on the region information.

- The list box shows the existing interfaces. You can right-click and select New to create a new interface or Delete to delete an existing one.

- Clicking on an interface from the list allows for the viewing and editing of its properties, including Side 1, Side 2 and Type. For details, see Type.

CFX-Pre will automatically attempt to determine the frame change and periodic regions. For details, see Type. Such interfaces are named according to the following: for two domains, `A` and `B`:

- Internal Interface connection in domain A: `A Internal Interface`

  Note: For Transient Blade Row cases using the Fourier Transformation method, a new internal interface is created between the two blade passages.

- Periodic connection in domain A: `A to A Periodic`

- Periodic connection in domain B: `B to B Periodic`

- Fluid-Fluid interface between domain A and B: `A to B <type>` or `B to A <type>`

  where <type> can be one of `Frozen Rotor`, `Stage`, or `Transient Rotor Stator`. For details, see Type.

Turbo mode in CFX-Pre supports automatic interface detection and creation only when each side of the interface consists of matching regions. The mesh does not need to match 1:1, but each region on one side of the interface must have a corresponding region on the other side of the interface. Meshes that do not satisfy this requirement can be used in Turbo mode, but it will be necessary to inspect and modify the interfaces that are created automatically in order to ensure that the interfaces are correct.

Release 18.2 - © ANSYS, Inc. All rights reserved.