Groups

Within preprocessors used with thermal solver, such as Simcenter 3D and Simcenter Femap, boundary conditions are often defined by pointing to a group of elements. Groups can also be used to define sets of elements that can be accessed from within a user written subroutine. This allows the development of user written subroutines that can be applied to many models.

As an example, you could develop a user-written subroutine for applying aero-heating loads to a model. Additionally, you could adopt the convention of placing any external element requiring aero-heating loads into a group called AERO_HEATED.At run time the user written subroutine will then resolve the contents of this group and apply the appropriate heat load. This subroutine could then be used with any model provided the user defines the group AERO_HEATED.

If a boundary condition is defined by referencing geometry, the methods described here will still work. As the thermal solver input file is built, geometry in groups is replaced by the associated elements. Thus, for user written subroutines, groups always contain elements.

The use of groups is the preferred method of referencing sets of elements to be processed in user written code. It provides greater flexibility than referencing elements by label.