3D Supermesh Design Workflow

The concepts needed to start with the workflows below have been already discussed in section 3D Supermesh. In this section below you just focus on the practical workflows.

Building a 3D Supermesh

A 3D Supermesh can be built based on a single map file or a group of map files. The first option will be used typically in situation, where a 3D geological model (structural data) is available. Alternatively, a 3D Supermesh can consist in a set of several map files, which all of them should follow two main requirements:

Contain proper 3D information (or definition).
Do not produce self intersection either by themselves or with other imported map files.

FEFLOW 7.5 can support a multiple number of file formats, being the most-commonly used below:

Geological models:

3D GeoModeller Files (*.gmod)
GOCAD 3D Model Files (*.ml)
GOCAD Surface Files (*.ts)
Leapfrog Mesh Files (*.lfm)
MineSight (*.dxf)

Generic 3D Files:

ESRI 3D Shape Files (*.shp)
Autodesk 3DS Files (*.3ds)
AutoCAD DXF Files (*.dxf)
VTK Files (*.vtu)

Meshing Files

TetGen Surface Mesh Files (*.smesh)
Triangle Mesh 3D (*.mesh)
STL Mesh Files (*.stl)

The map files needed for the 3D Supermesh construction can be imported using the New FEM Model Wizard ( File menu - New) with the Fully unstructured 3D mesh option and then Supermesh import from maps.

Storing Topological Information

Using Grouping Option

FEFLOW 7.5 provides the option of storing geometrical information from the imported map files. After each map import, the user can define a Grouping based on By Name or By Attributes options. The option of grouping based on file attributes will read on-the-fly the imported file and allow the user to decide which column in the map file should be used by the grouping. Common groups are created for those topologies, which share the same attribute value.

Using Region Markers

As discussed in section 3D Supermesh, a map file containing a list of point coordinates can be imported to build a supermesh. These points can be classified as Region Marker, Hole Marker, Point Add-ins or Custom. Their classification is defined at the option Type right below the name of the input map file. The Region Markers have the possibility to define the region (or volume) of the Supermesh for creating element selections in the Selections panel.

The concept of Region Markers is originally from the TetGen mesh generator. During the 3D meshing process, TetGen reads the list of markers and identifies the enclosed volume (or region), which contains the point. Knowing this information, the generator can distinguish those newly-generated tetrahedral belonging to the mentioned region. FEFLOW 7.5 takes fully advantage of this information by creating subsequently element selections with those tetrahedral.

For a proper definition of the regions, the list of points defined as Region Markers, they need to simply are contained within certain region. Thus, it is fully mandatory these points are properly 3D.

Example of a 3D Supermesh with Region Markers shown as a points in red color (left). Finite-element mesh created based on supermesh with element selection defined by markers (right).

3D Meshing

Finally, after a 3D Supermesh has been created, the user can proceed to generate a 3D finite-element mesh using the Meshing panel. Further details can be follow in section 3D Meshing.