SPARK3D User Manual
Mesh export from external software

In order to carry out the high power analysis with SPARK3D, first of all the electromagnetic fields must be computed for the frequency under study and exported in the format required by SPARK3D from one of the compatible electromagnetic software tools:

Besides, SPARK3D is also capable to import arbitrary DC fields computed with external software in the following formats.

Please refer to the Introduction for more information on features and limitations.

FEST3D®

It is quite straightforward to export the EM field from FEST3D to SPARK3D input format.

In the menu bar of FEST3D, click on Execute -> Export fields to SPARK3D to open the exportation window. The specifications window will appear so that you must set:

Click on Run button and the EM field will be exported in the proper format in a directory, whose name is the same as the .fest3 file. The recently created file has the extension .mfe and also has the same name as the .fest3 file.

ANSYS® HFSS v. 11 (or higher)

Requirements

In order to export the EM fields from HFSS™ to SPARK3D format you must take into account that:

It is important to point out that the fields should be given in peak values and correspond to an average input power of 1 W. So, the sum of the power levels in all excited ports must be equal to 1W.

Procedure

Once the electromagnetic response of the structure has been simulated and the EM fields have been computed for the frequency under study, you must follow the following steps:

  1. In the menu bar of HFSS™, go to Tools-> Run script and select the script named ExportToSpark3D.vbs, which has been distributed together with SPARK3D software. You can find it in the folder of SPARK3D installation, typically:

  1. SPARK3D standalone:  "C:\Progam Files(x86)\SPARK3D\dist\HFSSexportscript").
  2. SPARK3D with FEST3D: "C:\Program Files(x86)\FEST3Dx.y\bin\external \spark3d\dist\HFSSexportscript".

       

which will be used as input data in SPARK3D.

  1. Select from the Solids of HFSS model the ones corresponding to vacuum. Right-click on them and select the option Plot Fields->Named Expressions. From the displayed options, you must plot all the previously created variables, described in step 1. It is mandatory to use the variables created through the script. 
  2. Select the proper solution corresponding to one where the EM fields have been saved for the frequency under study.

  3. In the Project Manager, go to Field Overlays, right click on it and select the option Save As. Choose all the four Named Expressions presented before. They will be saved on a unique file of extension .dsp, that will be used as input data in SPARK3D.

Limitations

CST MWS® 2015 SP3 (or higher)

The exportation of the EM fields from CST MWS ® to SPARK3D is done as follows:

In CST MWS®, one just has to define two fields monitors for the same frequency: "E-field" and "H-field and Surface current". Once these monitors have been computed, click on the Home main menu in  Macros->Solver->F-solver->Export Fields to SPARK3D and a file with extension  .f3e will be created in the "Result" folder of the CST MWS®project. This file can then be imported from SPARK3D.

Limitations

CST MWS® 2012-2015 SP2

The exportation of the EM fields from CST MWS® to SPARK3D is done as follows:

In the menu bar of CST MWS®, click on Macros->Solver->F-solver->Export Fields to SPARK3D to open the exportation window. You must specify the frequency under study and the directory where the created file will be saved. The extension of this file is .f3e and it will be used as input data of SPARK3D.

Limitations

FEKO® 6.2

FEKO allows for automatically writing simulation results to a SPARK3D format . fse file. This is done as follows (please refer to the FEKO manual for more detailed instructions) :

Limitations

Export to near-field from FEKO to a SPARK3D file (i.e. near-field at points defined by a tetrahedral mesh) is only supported for dielectric volume regions with solution method set to FEM or VEP. Currently all dielectric volumes in a FEKO model must have the same solution methods setting (e.g. FEM regions are not supported together with a SEP or VEP regions in the same model).

Although FEKO writes boundary material information to the SPARK3D file, the current version of SPARK3D considers only vacuum/air regions for the analysis, and sets the same SEY curve for all boundaries (in multipactor simulations). 

DC Fields

ANSYS® MAXWELL

Once the magnetic or electric DC fields have been computed, you must follow the following steps:

  1. Select from the Solids of MAXWELL model the ones corresponding to vacuum. Right-click on them and select the option Fields->B->B_Vector, for magnetic field, or Fields->E->E_Vector, for electric field.
  2. Select the proper solution corresponding to one where the DC fields have been saved.
  3. In the Project Manager, go to Field Overlays, right click on it and select the option Save As. Choose the B_Vector (or E_Vector) box. It will be saved on a unique file of extension .dsp, that will be used as input data in SPARK3D.

CSV format

CSV (comma-separated-values) format files are text files with . csv extension that consist on tabulated data. SPARK3D can import DC fields which are saved in CSV format files, whenever the mesh is rectangular, structured and based on regular hexahedra.

Next, we describe the specific format that the CSV data should have in order to be imported by SPARK3D. Columns should be separated by one of the following characters: space, tab, comma, semi-colon. Each column represents a magnitude. Rows are separated by newlines. The format follows a 6-column scheme: x y z F DCx F DCy F DCz , being x, y, z the coordinates of each node in the mesh and F DC the values of the DC field.