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 The information provided may be out of date.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.

Question about potential calculation in MEF vs. EC

Please login with a confirmed email address before reporting spam

Hi,

I asked support this question, but am under pressure to figure this out soon, so I thought I would get some points of view from the forum as well, if I could. I'm doing a simple model of a coil right now. I need to see what happens between turns, so the multi-turn coil domain feature is not an option. I will be doing high frequency studies, but right now, I'm just doing stationary studies.

Anyway, when I apply voltage to one end of the coil (which extends to the edge of the domain) and ground to the other, it should be a relatively simple problem to find the voltage. It works fine in Electric Currents and the voltage is distributed evenly. I need to consider the magnetic field at higher frequencies, though, so I chose MEF. The results should be very close to the same for the stationary case. The MEF results, though, do not make sense, as the voltage is concentrated entirely at the end of the coil near the applied voltage.

Does anyone have any idea what might cause this? The model files are kind of large, so I have attached a couple of pictures to show what I'm talking about. The results should be almost exactly the same at DC, however they are not. What do you think?


3 Replies Last Post 2013年11月15日 GMT-5 12:32
Edgar J. Kaiser Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2013年11月14日 GMT-5 15:27

Adam,

you can clear mesh and solutions to shrink the model files. Without them it is difficult to give an advice.

Cheers
Edgar

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Adam, you can clear mesh and solutions to shrink the model files. Without them it is difficult to give an advice. Cheers Edgar -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2013年11月15日 GMT-5 06:51
Hello!

You should add "gauge fixing for A-field" to your Ampere's Law; this will correct your potential.
See also:
www.comsol.de/community/forums/general/thread/36745

Ralf
Hello! You should add "gauge fixing for A-field" to your Ampere's Law; this will correct your potential. See also: http://www.comsol.de/community/forums/general/thread/36745 Ralf

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2013年11月15日 GMT-5 12:32
Thank you so much Ralf, that works! I've been trying to figure this out for 2 weeks. Thank you!

A. J.
Thank you so much Ralf, that works! I've been trying to figure this out for 2 weeks. Thank you! A. J.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.