Creating the Interfaces

Setting up a simulation with airgap remeshing requires that you manually define interfaces. For airgap remeshing, you require a repeating interface between the airgap regions.

For this simulation, you create three types of interfaces:
  • in-place interfaces, including internal interfaces between parts of the same region, and contact interfaces between contacting regions
  • periodic interfaces between the side surfaces of the air regions
  • a repeating interface where remeshing occurs, that is, between the airgap fixed region and the airgap rotating region
For convenience, you first create these interfaces manually and then assign them to the correct part contacts using dynamic queries.

To create the in-place internal interfaces:

  1. Expand the Regions node.
  2. Right-click the Airgap_Fixed region node and select Create Interface.
    Simcenter STAR-CCM+ adds an interface, Airgap_Fixed/Airgap_Fixed, under the Interfaces node. By default, the interface type is Internal.
  3. Repeat the previous step for each of the remaining regions.


To create a contact-mode interface between the magnet and the rotating air domain:
  1. Multi-select the Magnet and Rotating region nodes.
  2. Right-click one of the selected nodes and select Create Interface > Contact-Mode Boundary Interface .
To create a contact-mode interface between the coils and the fixed air domain:
  1. Multi-select the Coils and Fixed region nodes.
  2. Right-click one of the selected nodes and select Create Interface > Contact-Mode Boundary Interface .
To create a contact-mode interface between the fixed airgap and the fixed air domain:
  1. Multi-select the Airgap_Fixed and Fixed region nodes.
  2. Right-click one of the selected nodes and select Create Interface > Contact-Mode Boundary Interface .
To create a contact-mode interface between the rotating airgap and the rotating air domain:
  1. Multi-select the Airgap_Rotating and Rotating region nodes.
  2. Right-click one of the selected nodes and select Create Interface > Contact-Mode Boundary Interface .
To create the periodic interfaces between the sides of the air domain:
  1. Right-click the Airgap_Fixed region node and select Create Interface.
  2. Repeat the previous step for the following regions:
    • Airgap_Rotating
    • Fixed
    • Rotating
  3. Expand the Interfaces node and multi-select the interfaces that you just created, that is:
    • Airgap_Fixed/Airgap_Fixed 2
    • Airgap_Rotating/Airgap_Rotating 2
    • Fixed/Fixed 2
    • Rotating/Rotating 2
  4. Right-click one of the selected interfaces and select Edit...
  5. In the Multiple Objects dialog, set the following properties:
    Property Setting
    Topology Periodic
    Periodic Transformation > Periodicity Rotational
To create the repeating interface between the airgap regions:
  1. Multi-select the Airgap_Fixed and Airgap_Rotating region nodes. Right-click one of the selected regions and select Create Interface > Contact-Mode Boundary Interface .
  2. Select the Interfaces > Airgap_Fixed/Airgap_Rotating node and set Topology to Repeating.
To assign the relevant part contacts to the interfaces that you just created:
  1. Multi-select all interface nodes. In the Contacts property, click .


  2. In the Multiple Objects - Contacts dialog, set the query to Type is Part Surface Contact and click OK.


    For each interface, Simcenter STAR-CCM+ automatically finds the relevant part contacts and sets the Contacts property. To visualize which contacts are assigned to an interface, you can open the query editor (). For example, the Coils/Coils interface includes two part contacts:

To simplify the navigation within the simulation tree, you can group the interfaces by topology:
  1. Right-click the Interfaces node and select Group By > Topology.


To check that the mesh is conformal at every interface, create a scalar scene:
  1. Right-click the Scenes node and select New > Scalar.
  2. Rename the Scenes > Scalar Scene 1 node to Conformal Mesh Check, and set the following properties:
    Node Property Setting
    Scalar 1
    Parts Parts select all regions
    Scalar Field Function Non-Conformal Interface Faces
  3. Save the simulation.