Steps of thermal project description in Flux 2D/3D
Presentation
The steps in the preparation of the thermal project are presented in this section.
Step 0 : project preparation
Project preparation (geometry, mesh, physics).
Attention: the thermal geometry must be the same as in the magnetic project. In fact, local data are exchanged.
Remark: in the case of Flux PEEC – Flux cosimulation, user has the possibility to import Flux PEEC geometry into Flux 3D through an object import of the .FLU project saved previously.
Step 1 : Create Spatial quantities
The first step is to create the spatial quantities that will store the losses values coming from the magnetic project, on each node of the thermal node.
For example : « JOULE » spatial quantity is created to store the joule losses. The spatial quantity type is « spatial quantity for multiphysics, real scalar » with an initial value of 0.
The spatial quantities creation is available through the menu
Step 2 : Associate the spatial quantities to the regions
To take into account the heat sources from the imported losses, the spatial quantities should be associated to the corresponding regions.
For that, in the region box the user must:
- Check the « possible thermal source »
- Choose the option « volume density by formula with spatial quantities »
- Enter in the formula the name of the spatial quantity
Step 3: Open the multiphysics context
Once the project definition is over, one must create a solving scenario that will be used for the magneto-thermal cosimulation. The multiphysics context can then be opened by using this scenario.
Remark : To open the multiphysics context in a thermal steady state project, one must create a void scenario (corresponding to a solving scenario with the reference values)The solving is available through the menu
Step 4 : Exporting the thermal nodes
Starting from the thermal project, the coordinates of the thermal mesh are exported to a .DEX file. These files are then imported into the magnetic project in order that the calculus and the losses export could be done onto the thermal mesh.
From this step, the magnetic and thermal projects have to be completed in parallel. User has to do the step 4 in magnetic project in parallel to this step, and so on for the other steps.
Remark: As to the choice of position of the mechanical set, it is advisable to choose the «position of reference». This permits the software to take the nodes of the first step and to avoid problems in case of non identical motion between the electromagnetic and thermal projects.The nodes export is available through the menu
Step 5: Create multipoints support
In the thermal project, multipoint supports are created to receive the magnetic mesh nodes. The calculus and the exports of temperature will be carried out on these nodes. For that, one must first export the nodes of the magnetic into the .DEX files (equivalent to the step 4).
The multipoints support creation is available through the menu
Step 6 : Create multiphysics formula
The entity «multiphysics formula» corresponds to the quantity or to the formula that will be calculated and exported. In the thermal project the formula to choose are:
- Predefined multiphysics formula « temperature »
- Or a multiphysics formula called «spatial formula» which allows user selecting a formula
Remark 1: Upon creating a multiphysics formula, a spatial quantity having the same name is automatically created. This permits the storage of calculated values in order to export them into magnetic.
Remark 2: A multiphysics formula equal to the sum of several multiphysics formulas will not work.
The multiphysics formula creation is available through the menu
Step 7 : 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, with the possibility of verifying if a support belongs to a region (it is advised to make this check to have the guarantee that the computation is done on the chosen region, especially on the regions border)
- The unit of length, the coordinate system, the position of the mechanical set (see step 4 above)
- The associated multiphysics formula
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 magnetic project.The creation of the data to export is available through the menu
Step 8 : 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 the spatial quantities created in step 1
- Region on which the spatial quantity is imported
- The unit of length, the coordinate system, the position of the mechanical set (see step 4 above)
- The importing method: «node to node» or «by proximity». In the thermal project, user have to choose «node to node» method (because the magnetic mesh is less concentrated)
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 magnetic project.
*The «node to node» method may not function, since the thermal and magnetic geometric accuracies are very different.The creation of the data to import is available through the menu
Step 9 : Create cosimulation
An entity named «Cosimulation» permits the definition of information concerning the cosimulation :
-
The type of cosimulation : Chose Flux-Flux.
In the case of a transient thermal, choose the number «n» of steps between each exchange of data, in order to synchronize the exchange with the magnetic project (the export will be done at every n steps)
- The folder of exchange must be the place where both the communication files and the exported results files are located.
- The relative accuracy of the convergence can be found in the magnetic project or the thermal project, but only in one of two. (acc. to remark in paragraph Steady state magnetic with steady state/transient thermal cosimulation ). In general, it is defined in the electromagnetic project in order to verify the imported temperature convergence. In the thermal project, user will choose “Convergence evaluation performed by third party software”.
- The list of data to export
- The list of data to import
The creation of the data to export is available through the menu
Step 10 : Solve
Once all the entities are created, it remains only to launch the solving process of the cosimulation in each of the two projects.
The creation of the data to export is available through the menu