This node is the default edge condition on shells. On external edges, this condition means that there is no heat flux across the edge:

Select the edges on which to apply a no flux condition. The Restrict to layered edges check box makes the node applicable only if a layered material is defined on the edge. If a layered material (Material with Layer thickness specified, Single Layer Material, Layered Material Link, or Layered Material Stack) is available, its name is then displayed beside the edge index (for example, slmat1), otherwise the edge is marked as not applicable.

Note that when the Shell type is Nonlayered shell in the Shells Properties section of the parent interface or node, the Restrict to layered boundaries check box is not editable.

In addition, in 2D, edges are modeled as points and this section is named Point Selection, containing a Restrict to layered points check box.

This section is available only when the Shell type is Layered shell in the Shells Properties section of the parent interface or node. You can limit the contribution to individually selected layers by clearing the Use all layers check box. For a given Layered Material Link or Layered Material Stack, you get access to a list of check boxes for the selection of the individual layers.

Physics Tab with Heat Transfer in Shells selected: