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 The information provided may be out of date.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.

Merging 2 models

I have a Comsol Model of a Maxwell Coil and a model of Helmhotlz coil with defined geometries. Now I want to make a simulation in which I can place these 2 coils together and simulate their magnetic flux density. How can I do that?

4 Replies Last Post Nov 29, 2012, 3:37 AM EST
Posted: 5 years ago Nov 26, 2012, 1:04 AM EST
Hi

you need to rebuild your model with both, and merge the physics into one as normally these two system will interact.

If you operate in stationary mode, you might use the sum of the two separate cases as a good starting point, in AC mode you might end up with cross coupling that changes far more your fields

--
Good luck
Ivar
Hi you need to rebuild your model with both, and merge the physics into one as normally these two system will interact. If you operate in stationary mode, you might use the sum of the two separate cases as a good starting point, in AC mode you might end up with cross coupling that changes far more your fields -- Good luck Ivar

Posted: 5 years ago Nov 27, 2012, 3:28 AM EST
Thanks. I successfully merged these 2 models. Now I want to get plot for ''Gradient'' of magnetic flux density. Is there a built-in operator for ''gradient (Del Function)'' ?

en.wikipedia.org/wiki/Gradient
Thanks. I successfully merged these 2 models. Now I want to get plot for ''Gradient'' of magnetic flux density. Is there a built-in operator for ''gradient (Del Function)'' ? http://en.wikipedia.org/wiki/Gradient

Posted: 5 years ago Nov 27, 2012, 5:21 AM EST
Hi

not for the gradient as such, but the component yes, check the doc, the dependent variables have their derivatives in subscript x,y,z,r,t respectively 2nd derivatives in xx,xy,yy,zz, tt...

but for vector fields the x,y,z,r might also define a coordinate component, this is context dependent, needs some time to learn

Not that by default the discretization is 2nd order (if your mesh i good), so you might derive 2 times, but the 2nd derivative is staircase function, in EM B is already the derivative of A, so deriving further might be done cleaner by increasing the discretization order of your model (but this increases the DoFs hence the need for RAM and time to solve)

--
Good luck
Ivar
Hi not for the gradient as such, but the component yes, check the doc, the dependent variables have their derivatives in subscript x,y,z,r,t respectively 2nd derivatives in xx,xy,yy,zz, tt... but for vector fields the x,y,z,r might also define a coordinate component, this is context dependent, needs some time to learn Not that by default the discretization is 2nd order (if your mesh i good), so you might derive 2 times, but the 2nd derivative is staircase function, in EM B is already the derivative of A, so deriving further might be done cleaner by increasing the discretization order of your model (but this increases the DoFs hence the need for RAM and time to solve) -- Good luck Ivar

Posted: 5 years ago Nov 29, 2012, 3:37 AM EST
I made mph model and to calculate gradient i want to import mph model in MATLAB. Is comsol 4.3 compatible with matlab R2011a?

I made mph model and to calculate gradient i want to import mph model in MATLAB. Is comsol 4.3 compatible with matlab R2011a?

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.