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FEM Mesh Group

In one sentence: Define a named group of mesh faces or elements — required for Elmer to associate boundary conditions with specific faces.

Overview

Workbench: FEM
Menu: FEM → Mesh → FEM Mesh Group

Defines a named group of mesh elements (faces, edges, volumes) that is written into the Gmsh mesh file. Named groups are required by Elmer to identify which boundaries receive which boundary conditions.

Why it matters for Elmer

Elmer identifies boundary faces by group names in the mesh file. Without named groups, Elmer cannot correctly assign boundary conditions. All Elmer analyses should use Gmsh + FEM Mesh Group.

Step-by-step

  1. Add a Gmsh mesh first.
  2. Choose FEM → Mesh → FEM Mesh Group.
  3. Select the face(s) to include.
  4. Enter a Name for the group (e.g. inlet, wall, outlet).
  5. Click OK and regenerate the mesh.

Common mistakes and pitfalls

Elmer requires named Gmsh mesh groups

If a Netgen mesh was used (which has no physical groups), Elmer cannot correctly apply boundary conditions. Regenerate with Gmsh and add Mesh Group objects.

See also