Boundary layer

Menu: Mesh->Boundary layer

A boundary layer mesh is one mesh attached to the boundary, and which has a specific distribution of nodes separated from the boundray following a given stretching function. The streching function and the grow factor of the boundary layer meshes of a model can be set in Preferences.

Only tetrahedra or triangle elements are generated in the boundary layer mesh, and there is no transition elements for conecting tetras to other kind of elements in the 'isotropic' mesh, so the mesh of the volume or surface which has a boundary layer mesh must be of tetrahedra or triangle too.

• 2D option allows the user to assign or unassign the boundary layer properties to the lines selected by the user. First of all, the user selects the surfaces the boundary layer will grow into. The boundary layer mesh will begin from the lines and will grow into the surfaces.

• 3D option allows the user to assign or unassign the boundary layer properties to the surfaces selected by the user. First of all, the user selects the volumes the boundary layer will grow into. The boundary layer mesh will begin from the surfaces and will grow into the volumes.

• Reset option reset all the boundary layer mesh information attached to the model.

User can define two main properties to the boundary layer meshes of each geometrical entity: 'First layer height' and 'Number of layers'. When selecting the entities which will have boundary layer mesh a window shows a schematic picture, where user can see the distribution of heights of each layer, and the total height of the boundary layer mesh when the assigned properties are set.

Quadratic elements are not allowed for Boundary layer meshes.