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plasma needle and fluid equations
Posted Mar 7, 2011, 4:54 p.m. EST Plasma Physics, RF & Microwave Engineering, Modeling Tools & Definitions, Parameters, Variables, & Functions 1 Reply
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Hi, everybody
I have been trying for 5 months to solve a set of 8 equations and variables (plasma fluid equations)
But couldn’t yet. I use comsol3.4 for to handle it. In addition I am forced to solve those equations in spherical coordinates (r component dependent).
I have some problems.
The simulation geometry is as follow:
A ………………………………………………... B
Please help me with these problems :
1) There is no default spherical coordinates in the comsol. Now how can I resolve this problem?
2) My simulation mesh grids should have these characteristics :
a: the minimum mesh size in the A- point should be 1 micrometer and 5 micrometer in the B-point, that gradually expended up to 10 micrometer in a point at the middle of A and B.
b: the total number of meshes is supposed to be 180.
Unfortunately, I am not able to define meshes with these characteristics.
3) The applied voltage in the A-point is as “v*cos(f*t) “( f is voltage frequency) and the B-point is grounded. Using Time-dependent solver with that voltage function result in solution which are incorrect from the view point of plasma physics. Also, when I applied stationary solver we get this error report:
“the time variable t, in voltage expression v*cos(f*t) for the A point is unknown”.
Regards
parviz
I have been trying for 5 months to solve a set of 8 equations and variables (plasma fluid equations)
But couldn’t yet. I use comsol3.4 for to handle it. In addition I am forced to solve those equations in spherical coordinates (r component dependent).
I have some problems.
The simulation geometry is as follow:
A ………………………………………………... B
Please help me with these problems :
1) There is no default spherical coordinates in the comsol. Now how can I resolve this problem?
2) My simulation mesh grids should have these characteristics :
a: the minimum mesh size in the A- point should be 1 micrometer and 5 micrometer in the B-point, that gradually expended up to 10 micrometer in a point at the middle of A and B.
b: the total number of meshes is supposed to be 180.
Unfortunately, I am not able to define meshes with these characteristics.
3) The applied voltage in the A-point is as “v*cos(f*t) “( f is voltage frequency) and the B-point is grounded. Using Time-dependent solver with that voltage function result in solution which are incorrect from the view point of plasma physics. Also, when I applied stationary solver we get this error report:
“the time variable t, in voltage expression v*cos(f*t) for the A point is unknown”.
Regards
parviz
1 Reply Last Post Mar 10, 2011, 1:38 a.m. EST
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Posted:
1 decade ago
Hi, everybody
I have been trying for 5 months to solve a set of 8 equations and variables (plasma fluid equations)
But couldn’t yet. I use comsol3.4 for to handle it. In addition I am forced to solve those equations in spherical coordinates (r component dependent).
I have some problems.
The simulation geometry is as follow:
A ………………………………………………... B
Please help me with these problems :
1) There is no default spherical coordinates in the comsol. Now how can I resolve this problem?
2) My simulation mesh grids should have these characteristics :
a: the minimum mesh size in the A- point should be 1 micrometer and 5 micrometer in the B-point, that gradually expended up to 10 micrometer in a point at the middle of A and B.
b: the total number of meshes is supposed to be 180.
Unfortunately, I am not able to define meshes with these characteristics.
3) The applied voltage in the A-point is as “v*cos(f*t) “( f is voltage frequency) and the B-point is grounded. Using Time-dependent solver with that voltage function result in solution which are incorrect from the view point of plasma physics. Also, when I applied stationary solver we get this error report:
“the time variable t, in voltage expression v*cos(f*t) for the A point is unknown”.
Regards
parviz
Dear Parviz,
I think your described problem is very specific and that's why nobody posted any reply yet. And furthermore, you have asked many questions in just a one post and that's a bit confusing and tiring! So in my point of view, create another post and ask just your most important question more generally without any irrelevant information and extra details. Then, when you get your answer from that post you can specify your question more and more. But always keep this in mind that your question shouldn't be very general or specific here.
and one more thing! try to make your topic tags more; for example, put "Plasma", "RF", "PDE", "needle", and any other word that comes to your mind!!! that helps others find your post and guide most talented and relevant experts to your post.
Wish you good luck!