Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Consistency of Plasma Discharge multiphysics model (V4.1)
Posted 20 mars 2011, 19:47 UTC−4 Plasma Physics, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.1 1 Reply
Please login with a confirmed email address before reporting spam
I am making a model of Plasma discharge and the expansion of the plasma which follows that discharge. I have 4 modules involved:-
1. Drift Diffusion module (dd) to model electron generation and heating.
2. Heavy Species Transport (hs) to model ions and neutrals interactions.
3. Non isothermal flow module (nitf) to model the temperature of heavy species and to study flow velocity due to heating.
4. Electrostatic module (es) to define the voltage which will be used to drive electrons and ions in the plasma.
My problem is regarding the consistency of the different modules, for example there is temperature defined in 'hs' as 'hs.T'' and there is temperature defined in 'nitf'; so which one represents the temperature of the heavy species?? what is the difference between them??
The same is true for pressure there is 'hs.pa' and 'nitf.p'; which one is the pressure and what is the difference?
The last thing regarding the consistency is the computation of current; physically speaking the current carriers are defined by electrons and ions which are given by ''dd'' and ''hs'' modules, my question is; does the ''es'' module count those carriers automatically or I have to include them in the expression for conductivity??
Unfortunately I have not managed to run the model even once because I am encountering a problem ''Failed to evaluate variable Jacobian'', that message is given for a variable called ''hs.ebar'' although it doesn't exist, how can I solve this problem??
Sorry for my long post, thanks for your help.
Hello Mo Sayed
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.
Please login with a confirmed email address before reporting spam
I'm getting the same problem the hs.ebar while coupling electroestatics and heavy species. Indeed I haven't had much time to serach for a solution. But I've been seraching in th equation view inside the hs module and I haven't found the variable, but for other plasma modules I've seen it refers to the Mean Electron Energy, which is found as an input in the electron specie.
I've seen I'm quite late answering however... The temperature used for heavy species, if I am not wrong, is used to calculate the number of neurtal species using the ideal gas law gas at a temperature hs.T (which is a macroscopic variable).
About the conductivity, I've to say what first come to me is to compute it manually and then add the property as alook-up table on ES module, but I haven't tried.
If you have solved your problem, I would be greatfull to know how!
Regards,
JH