Hello,
We are simulating an EP thruster plume (SPT100) in an on-ground chamber with SPIS 6.0.4 and 6.1.0 and experience the following problem: The proposed global parameter setting of using a groundedPotFlag = 1 leads to a wrong plasma potential in the EP plasma plume. See the following example plots for a simulation with groundedPotFlag = 1 (the thruster node is connected to the ground node by a 50 kOhm resistance):
It can be observed that: -The cathode potential stays at 0 V -The plasma potential is negative -The cathode emitted current does not converge and increases arbitrarily to very large values This behavior is obviously wrong and changing the parameter to groundedPotFlag = 0 leads to much more meaningfull results:
Can you tell me, what is the meaning and the correct use of the parameter groundedPotFlag?
Thanks a lot for your support!
Jens
Dear Jens,
this behavior is normal if you have set open boundaries in your domain. the cathode current is computed from the electron flux extrapolated at infinity. This normally leads to an increase of the cathode potential to a value where the electron and ion currents are equal at infinity. If you force your cathode to 0V, then the electron current cannot be limited anymore and becomes very large.
To model a grounded thruster on the ground, you have to set closed (metal) boundaries.
Hello，Jens
Recently I Have been working to simulate the plume produced when solar wind intereacts with a body, but I do not know how to display the 3Dplot of the plume as you did in the picture that you put above.Do I need to modify the globle parameters or do the other things to get such plume 3dplot you put above? And also,Exactly, I do not know how to set the direction and location of particle(ions and elctrons) injection.
Thanks a lot for your support!
hello，Jens，I have a question，I want to know how to use ‘‘groundedPotFlag’’, or where is ‘‘groundedPotFlag’’? how to set ''groundedPotFlag = 1 ‘’？
I would be grateful if you could help me！
thanks！
