Steps of magnetic project description in Flux PEEC

Presentation

The steps in the preparation of the electromagnetic project, for a co-simulation with Flux 3D thermal project, are presented in this section.

The physical application in Flux PEEC which is concerned by the co-simulation is a steady state AC magnetic application defined by one or several frequencies.

Step 1: geometry, mesh and physical application

In case of new project:

  • Choose the physical application dedicated to the magneto-thermal application: Supplied conductors with thermal coupling.
  • Define a solving scenario with one or several frequencies for the study. (In case of multi-values for the frequency, the exported losses correspond to the sum of the losses for the different frequencies).

  • Create or import the geometry.

    Attention: the thermal project geometry generated successively must be the same as the electromagnetic project geometry. In fact, local data are exchanged.

  • Generate the mesh

Remark: user has the possibility to switch from “supplied conductors” application to “Supplied conductors with thermal coupling” application without losing physical data of the project.

Step 2: Create the T dependent materials

Create the materials with a temperature dependant J(E) model and associate it to the concerned unidirectional or bidirectional conductors, or modify existing predefined materials J(E) properties.

Several temperature dependant J(E) models exist. The most commonly used model is “Isotropic resistivity, linear function of T”.

Step 3: Open the multiphysics context

Once the project definition is over, open the multiphysics context through the solving scenario in order to set the cosimulation data.

Attention: any parametric scenario defined by a parameter which is not the frequency (geometric or physical) doesn't allow to make cosimulation.

The multiphysics context can be opened through the menu Solving > Multi physic solving session (existing scenario)

Step 4: Exporting the electromagnetic nodes

Starting from the Flux PEEC project, export in .DEX files the electromagnetic nodes coordinates corresponding to the Flux PEEC mesh elements barycenters.

Those files are then imported in the thermal 3D Flux project in order to make the thermal computation and export on those barycenters / magnetic nodes.

From this step, the magnetic and thermal projects have to be completed in parallel. User has to do the step 4 in thermal project in parallel to this step, and so on for the other steps.

The nodes export is available through the menu Parameter/Quantity > Export nodes of regions

Step 5: Create multipoints support

In Flux PEEC project, create multipoint supports with thermal mesh nodes. The losses computation and export will be done on thermal mesh nodes. (for that, user has to export before the thermal nodes coordinates (equivalent step 4)

Remark: the losses value exported from Flux PEEC corresponds to the value computed on the mesh element which has the nearest barycentre to the considered thermal node.

The multipoints support creation is available through the menu Coupling tools > Multi point support > New

Step 6: Create data to export

An entity named «Data to export» permits the definition of information concerning what is being exported:

  • Multipoint support where the multiphysics formula will be calculated
  • The unit of length and the coordinate system
  • The multiphysics formula JOULE_LOSSES created by default

Each data to export corresponds to an exported file.*

*NB: the name of the data to export must be exactly the same as the name of the data to import in the thermal 3D project.

To create data to export go to the menu Coupling tools > Exported data > New

Step 7: Create data to import

An entity named «Data to import» permits to define the information concerning what is being imported:

  • Spatial quantity which will store the value to be imported : choose TEMPERATURE which is created by default
  • The unit of length and the coordinate system

As explained in the previous section, the name of a data to import must be exactly the same as the name of the equivalent data to export defined in the thermal project.

To create data to import go to the menu Coupling tools > Imported data > New

Step 8 : Create cosimulation

An entity named «Cosimulation» permits the definition of information concerning the cosimulation :

  • The type of cosimulation : choose “Flux-Flux cosimulation”
  • The folder of exchange must be the place where both the communication files and the exported results files are located
  • The defining of the loop interruption mode: choose “convergence evaluation performed by this project”. In fact, for a Flux PEEC–Flux 3D cosimulation, it would be better to evaluate the convergence in Flux PEEC on the imported temperature. In Flux 3D, the choice would be then “Convergence evaluation performed by third party software”.

The relative accuracy of the convergence can be kept by default (1%).

  • The list of data to export
  • The list of data to import

To create cosimulation entity go to the menu Coupling tools > Cosimulation > New

Step 9 : Solve

Once all the entities are created, it remains only to launch the solving process of the cosimulation in each of the two pieces of software, through the menu Multiphysics solving > Solving the cosimulation > New