The mesh process (advanced user)

Meshing

The table below illustrates possible mesh strategies the user may select in order to mesh a project using various tools (mesh generators and adjustments) available in Flux.

Stage Description
1

Preliminary consideration: choose a mesh type

  • automatic mesh (single mesh generator)
  • mixed mesh (multiple mesh generators)
2

If mixed mesh

Then definition of the different areas

  • and use of generic mesh generator
  • or creation of user mesh generator

for these different areas
3

Preadjustment of meshing

Reflection on the adjustment mode

  • global with the Aided mesh (see Aided mesh )
  • and/or local (user adjustments)
4 Mesh construction (creation of line, surface, volume elements)
5 If necessary , readjustment of various adjustments and return to stage 4
6 Choice of the type of elements: 1st order or 2nd order

Mesh strategy (1 and 3)

Phases 1 and 3 of the meshing process are consideration phases on the choice of mesh generators and the adjustment mode. For assistance making this choice, see the sections on mesh generators (see Fully automatic meshing or mixed meshing : comparison ) and the adjustment tools (see The adjustments (mesh size) .

Creation, mesh generator assignment (2)

This stage concerns the possible creation of user mesh generators and assignment of mesh generators to the different areas.

In the case of mixed mesh, the user can:

  • use the « generic mesh generators » :

    automatic (with or without deviation control) , adjusted or without meshing

  • or use his own mesh generators (linked or extrusion mesh generators)

Important:

Attention: In the geometry context, if the building options “with mesh” are activated during the propagation and/or extrusion phases, linked and/or extrusive mesh generators are automatically created.

Adjustment and mesh (3 and 4)

Mesh and mesh adjustment are two interdependent processes:

  • meshing (subdivision of lines, faces and volumes) is carried out by the software
  • the adjustment (Aided mesh and/or adjustments created by the user) is made by the user

The complete process is represented in the diagram below.

The adjustment principles are described in the section "The adjustments (mesh size).

Choice of the type of elements (6)

This last phase of mesh process is specific to volume mesh. For 2D mesh, elements created are automatically 2nd order elements.

In general, generating second order element is a better strategy, however it could be useful, in certain configuration to solve a problem with first order element (computation time, memory size problem,…).

Mesh and geometry

The user generally proceeds with successive steps and it is possible to repeat several building geometry processes and several mesh construction processes. Thereby going back and forth between geometry and mesh contexts (see examples hereafter). For instance,

  • When modeling a motor, the user can create the geometry of a slot, assign mesh information, and propagate the slot with mesh information already defined.
  • The mesh of an air gap can be facilitated by adding points and lines that are useless to the build regions.

This is illustrated in the figure below.

Note: in order not to be constrained to create supplementary points and lines, the user can resort to Aided mesh . Consideration of the geometry will refine the mesh in the neighborhood of the rectangle, and the relaxation will lighten up the mesh as one moves away from the rectangle.