[Archive] Different initial potential for different physical surfaces

Message by Marco Chiaretta:
Hello to the community,
I run spis 3.7RC09 and I should solve this problem:

I run simulations with a fixed potential => electriCircuitIntegrate=0 on a model represented by a single .geo main file that has 4 physical surfaces and 1 physical volume defined at cad (Gmsh) level. The "spacecaft" itself is defined trough 3 different physical surfaces and these 3 components are connected without surfaces in the between. So there is only one topology. e.g.: it is like labeling a cubic spacecraft with 3 physical surfaces hence, 2 contiguous faces are physical surface1, 2 other faces are physical surf.2 and the last 2 faces=physicalsurf.3. I want to look at the collected current over each one of the 3 surfaces. In the case I'm examinating with this simulation, the first and the second physical surfaces must have the same potential and represent a probe and a stub. A third physical surface is the spacecraft body and it has to be setted to another potential. Question
I haven't succeed in defining these 2 different potentials.In fact, when Spis is running, all the nodes show the same potential. How to generate this difference?
I have tried different approaches by editing the circuit.txt file and by editing the "iniPot=...." in the spacecraft window of the Spis control panel. Can you please suggest a solution for this problem?Thank you Marco Chiaretta

Message by Jean-Francois Roussel:
you set the global parameter initPotFlag to 2, and define the local potential you want on your local groups (SCDiriPot = your local potential) by modifying your “plasma properties” (one different “plasma” per potential value you want to set).
If you have a SC circuit (not needed when electriCircuitIntegrate=0, normally you would not use one), the constraints coming from the circuit will override you predefined potentials.
It should work properly (it was ofetn used).

Message by Marco Chiaretta:
thanks for the fast reply,
where can I find the setting “SCDirIPot=”?
Thank you

Message by Jean-Francois Roussel:

  • in the plasma properties to modify them
  • in the group editor to assign them to groups