Creating a Hub Interface

In simulations that require heat conduction through solid shells or solid regions, hub interfaces permit transfer of heat flux solution data. A hub interface can be created between:

  • Shell edges and shell edges.
  • Shell edges and shell surfaces.
  • Shell edges and 3D solid surfaces.

A hub interface needs at least one shell edge to be formed correctly. You can create hub interfaces at the parts level or at the boundary level. At the parts level, you can choose either curves from shell parts or surfaces from shell or 3D solid parts (provided they are already assigned to shell or solid regions).

At the boundary level, you can choose either edge boundaries from shell topology regions or surface boundaries from shell topology or solid volume topology regions. For details on creating parts-based shells, see Creating Parts-Based Shells.

There are several ways to create a hub interface.
Creating a Hub Interface under the Boundaries Node
To create a hub interface under the Boundaries node, select one or more shell boundaries (shell or 3D solid surfaces or shell edges), right-click on them, and select Create Hub Interface.


This action creates a new hub interface underneath the Interfaces node and default boundaries as follows:
  • For shell edge-shell edge hub interfaces, one default edge hub interface boundary in each shell region connected by the hub interface.
  • For shell edge-shell surface hub interfaces, two default hub interface boundaries (one edge and one surface) in each shell region connected by the hub interface.
  • For shell edge-3D solid surface hub interfaces, two default hub interface boundaries (one edge and one surface) in each shell region, and one default hub interface boundary (one surface) in each 3D solid region connected by the hub interface.


Creating a Hub Interface under the Geometry Parts Node
To create a hub interface under the Geometry > Parts node, expand the Surfaces or Curves nodes under the target [3D solid parts] or [shell parts] nodes, select the constituent surfaces or curves, right click, and select Create Hub Interface. The 3D or shell parts must already be assigned to 3D or shell regions before this option appears.


This action creates a new hub interface underneath the Interfaces node and default boundaries as follows:
  • For shell edge-shell edge hub interfaces, one default edge hub interface boundary in each shell region connected by the hub interface.
  • For shell edge-shell surface hub interfaces, two default hub interface boundaries (one edge and one surface) in each shell region connected by the hub interface.
  • For shell edge-3D solid surface hub interfaces, two default hub interface boundaries (one edge and one surface) in each shell region, and one default hub interface boundary (one surface) in each 3D solid region connected by the hub interface.
Creating an Empty Hub Interface from Interfaces
The Interfaces node must be available in the simulation tree. Right-click the Interfaces node and select New Hub Interface > Boundary Mode or Part Entity-Mode.

No hub interface boundaries are created by this action.

Creating an Empty Hub Interface from Regions
The regions must be solid shell regions or solid 3D regions. Select one or more regions and right-click on them. The Boundary-Mode Hub Interface and Part Entity-Mode Hub Interface options become available under Create Interface.

Modifying an Existing Hub Interface Boundary

When the number of edge parent boundaries or curves of a hub interface in a particular connected region is greater than the number of edge hub interface boundaries (tied to the same hub interface) in the same region, you can create additional secondary edge hub interface boundaries. Right-click on an existing (default or secondary) hub interface boundary, and select Add Hub Interface Boundary. This action can be done for either boundary-based or parts-based hub interfaces. This action creates an empty secondary hub interface boundary in the same region (without the hub icon ), connecting to the same hub interface.

The same principle applies to surfaces that participate in hub interfaces also.

Initializing or Resetting the Hub Interface

Initializing the hub interface is similar to initializing any other interface in Simcenter STAR-CCM+. You can either right-click on the specific hub interface and select Initialize to initialize only this interface. Alternatively, right-click on the Interfaces manager and select Initialize to initialize all interfaces in the simulation tree.

Resetting a hub interface is also similar to resetting any other interface in Simcenter STAR-CCM+. You can either right-click on the specific hub interface and select Reset to reset only this interface or right-click on the Interfaces manager and select Reset All to initialize all interfaces in the simulation tree. Simcenter STAR-CCM+ reverts the interface back to the state before initializing them.

Hub Interface Properties

You can use the properties that are listed below to adjust the specifications of the Hub Interface node.

Geometry
Specifies the geometry source option:
  • Boundaries: The interface is a boundary-mode interface, which is created by selecting one or more boundaries.
  • Part Entities: The interface is a parts-mode interface, which is created directly by selecting one or more part curves or surfaces.
Connected Regions

Specifies the regions that are connected to the hub interface. The Connected Regions property of the hub interface updates automatically based on the updated parent boundaries or entities selection.

Parent Boundaries/Part Entities

Specifies the boundaries or part entities that are associated with the hub interface. You can add or remove parent boundaries or part entities from the custom editor dialog. Dynamic queries can also be used to make this selection.

A hub interface boundary cannot be deleted if it is not empty—that is, if it has one or more parent boundaries or curves or surfaces. The default hub interface boundary cannot be deleted. Only secondary, empty hub interface boundary can be deleted.

Type

Defines the type of interface.

Tolerance
Located within the Physics Values child node for a hub interfaces and governed by the Absolute/Relative selection set by Tolerance Option. This value specifies the maximum normal distance between face centroids for hub interface intersection. Keep this value as low as necessary for obtaining the appropriate intersection. Too high a value can result in unexpected intersections.
Tolerance Option
Allows you to choose between Absolute or Relative sizing for the tolerance. When set to Relative, the tolerance is a fraction of the maximum edge length of the boundaries involved in the interface. When set to Absolute, the tolerance is whatever value and unit you specify.