3D Example: Geometry and mesh (Tutorial)


This paragraph is a summary of cases treated in detail in the technical document: "3D Generic Tutorial".

Flux files, relating to these various cases, are available on the CDROM of documentation of the software.

Realized study

The study proposed in the 3D Generic Tutorial of Geometry and Mesh is the study of a variable reluctance speed sensor. Only the geometry model and mesh of the device are studied in this tutorial.

Studied device

The variable reluctance speed sensor consists of a cogged wheel, a magnet and a coil connected to a measuring resistance.


The rotation of the target wheel near the tip of the sensor changes the magnetic flux, creating an analog voltage signal that can be recovered in probes.

Geometric structure in Flux

The device is described in Flux as follows:

  • one cogged wheel with three teeth
  • two probes with a magnet and a coil around


Two strategies of description exist:

  • one-phase description:
    • description of the whole device in only one Flux project
  • two-phase description:
    • independent description of separated parts of the device in several Flux projects
    • merging the independent projects into one

The second strategy is selected in this tutorial.

Of course, the geometry can be built in ways other than the presented one. The sensor geometry is defined in this particular way in order to introduce you to the most used Flux features.