COMSOL 6.3 - Sector Symmetry Pair

) to specify a pair between two domains while modeling a sector of a geometry and one of the domains is rotating around the sector center. If you select sector symmetry pairs instead of identity pairs in a feature in a physics interface, the sector settings in the physics feature are no longer needed. You instead specify them in the sector symmetry pair..

	The easiest way to set up a sector symmetry can often be to use the identity pair that is added automatically for an assembly geometry, an in its settings select the Manual control of selections and pair type checkbox and then change the pair type to Sector symmetry pair. You then do not need to identify the pair boundaries in a separate Sector Symmetry Pair node.

	Go to Pair Name for information about the Settings window Pair name. Also see Settings and Properties Windows for Feature Nodes.

This section is the described for the Identity Pairs except that the default is .

The destination boundaries should overlap the source boundaries. The condition that connects the physics nodes on the destination and source boundaries is specified in the physics interface. For example, it can be a constraint that constrains a dependent variable (temperature, for example) on the destination side to be equal to a dependent variable on the source side. In this case, the boundaries and domains on either the source or destination, or both side, are rotating around an axis, so the boundaries do not need to be in contact in all cases but rather for some angles only.

To define the source or destination boundaries, from the lists, choose , , or any other available selection for the boundaries on the source or destination side. If is selected, click in the window to add boundaries to the section. If required, click the button (

) to swap the source boundaries and the destination boundaries.

Click the button to toggle between turning ON

and OFF

selections directly in geometry, for example. Such selections also become active when you choose from the list.

The inputs needed in the sector symmetry pair is the number of sectors, the rotation axis base point, and (in 3D) the axis of rotation. These settings can be computed automatically from the geometry in simple cases. Otherwise, you must provide them by choosing from the list (default: ). When you choose , also specify the following:

•

: define the base point for the rotation in the , (2D and 3D), and (3D) fields.

•

(3D only): define the axis of rotation in the , , and fields.

Use this settings to control the frame to use for the pair. Choose (the default), , , or .

The value in the field is used to find out if two points are in contact or not (default: 0.05).