Menu

Discussion Forum

New Discussion
Filter

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.

Arrow surface in 2D model (Transport of diluted species) and value of flux from arrow

Posted Jan 19, 2015, 7:05 a.m. EST Chemical Reaction Engineering Version 5.0 6 Replies

Eva Deutekom
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Dear Community,

I built a 2D model with the transport of diluted species physics. I would really appreciate some help with reviewing the results.
I want to plot the species flux (total flux/diffusion flux etc) as an arrow surface plot. When plotting an arrow surface plot, there is a choice between arrow lengths "proportional, normalized and logarithmic". The choices seem pretty straight forward in what they do.
Now it seems I have fluxes that are really small, so in the default ("proportional") option, I cannot see the arrows.
Now I have two questions concerning the arrows:
1. how can I find the value that belongs to the arrow length (i.e. I want to know how small these fluxes actually are).
2. If I use the normalized option, I will see the fluxes, but how "bad" wil the errors be the cause of these flux arrows?

Kind regards and thank you greatly in advance,
Eva
6 Replies Last Post Mar 8, 2016, 11:10 p.m. EST
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jan 19, 2015, 10:13 a.m. EST
Hi Eva,

the arrow length is determined by the absolute value of the field variable you are plotting. I sometimes plot the logarithm of this quantity if I want to visualize a large range of many orders of magnitude. In case of a magnetic flux the components would look like: log10(normB)*Bx/normB.

Hope this helps,
Edgar

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hi Eva, the arrow length is determined by the absolute value of the field variable you are plotting. I sometimes plot the logarithm of this quantity if I want to visualize a large range of many orders of magnitude. In case of a magnetic flux the components would look like: log10(normB)*Bx/normB. Hope this helps, Edgar -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com
Eva Deutekom
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jan 19, 2015, 10:55 a.m. EST
Dear Edgar,

Thank you kindly for your reply.
I am still wondering if there is a way to obtain these arrow length values (or in other words the absolute value of field variable)? Like a "scale" for instance.

Kind regards,

Eva
Dear Edgar, Thank you kindly for your reply. I am still wondering if there is a way to obtain these arrow length values (or in other words the absolute value of field variable)? Like a "scale" for instance. Kind regards, Eva
Eva Deutekom
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jan 19, 2015, 11:17 a.m. EST
PS:

Is there any documentation on this and the topic? I cannot find it in the comsol documentation.

Kind regards,

Eva
PS: Is there any documentation on this and the topic? I cannot find it in the comsol documentation. Kind regards, Eva
Edgar J. Kaiser Certified Consultant
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jan 19, 2015, 2:12 p.m. EST
I am not sure I uderstand what you need. As far as I am aware the absolute value for any field is always available as the 'normfield', e.g. normB. Or you can use sqrt(fieldx^2 + fieldy^2 + fieldz^2) or some other expression for the norm of the field. Replace the string field by the field name you need.

--
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
I am not sure I uderstand what you need. As far as I am aware the absolute value for any field is always available as the 'normfield', e.g. normB. Or you can use sqrt(fieldx^2 + fieldy^2 + fieldz^2) or some other expression for the norm of the field. Replace the string field by the field name you need. -- Edgar J. Kaiser emPhys Physical Technology http://www.emphys.com
Eva Deutekom
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jan 20, 2015, 4:31 a.m. EST
Dear Edgar,

I understand now (sorry, took me a while). This helps.
Thank you very much!
Kind regards,

Eva
Dear Edgar, I understand now (sorry, took me a while). This helps. Thank you very much! Kind regards, Eva
Eason Chen
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago Mar 8, 2016, 11:10 p.m. EST
Dear Edgar
Could you please introduce me with the function of range quotient under the option of logarithmic in the section of arrow length?
Dear Edgar Could you please introduce me with the function of range quotient under the option of logarithmic in the section of arrow length?

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.

Suggested Content