To maintain a topology viable for hexahedral meshing (i.e., 6 faces per volume, multi-block mesh) you often have to resort to multiple-connected volumes. Also if you want to assign different initial conditions to different regions within a flow domain you will need to create a flow domain with multiple-connected volumes.

Multiple-Connected Flow Domain

Assumptions

1. You have downloaded, installed, and activated Caedium Professional.
2. You are familiar with Caedium essentials.

Procedure

1. Create multiple volumes to cover your flow domain. If you want to use the structured hexahedral meshing technique then maintain 6 faces per volume.
2. Use the Faces->Connect tool on the Geometry Tool Palette to connect the shared face(s) between your volumes.
3. Create a group of the connected volumes.
4. Add your Substance to the group not the volumes.
5. Assign your boundary conditions (BCs) as normal, but don't assign any BCs to the internal connected faces.
6. Each volume in the group will now have its own Physics::Initial conditions that you can specify separately.