Objects relative positions and EM study

[giulian]

Dear Elmer Community,

I would like to model the EM field of two objects in air at different relative positions. So my conditions are the following:

• the air frame has a boundary behaving as a port (incoming plane em wave)

• one small object is "moving" at different position on the surface of the other object. I put the word MOVING in quotation marks because i'm not interested in transient solution but just static ones

So now my questions are the following:

• Can I parametrize the position of an object in Elmer?

• if not, is it possible to create a way to automatize the procedure elsewhere and implement it in Elmer?

• In post-processing phase, is possible to create a video/clip with those multiple simulations? ( in Elmer or in Paraview e.g.)

Thank you very much for the help and any possible suggestions
Cheers

[kevinarden]

something similar
viewtopic.php?t=7912

I may be able to find some other examples of similar.
Basically using rigidmeshmapper to move objects around
Chapter 42
https://www.nic.funet.fi/pub/sci/physic ... Manual.pdf

[kevinarden]

here is another example

rotating.mp4

(463.84 KiB) Downloaded 85 times

rotating.zip

(165.59 KiB) Downloaded 81 times

[kevinarden]

Same geometry with rotating object magfield

magrot.mp4[/attachment [attachment=0]system.sif

[giulian]

Dear Kevin,

thank you very much for your feedback, however in my case the simulation is 3D and the small object has a rather specific form and a specific trajectory. would it be possible to create different meshes for each position and then feed it to the solver in an iterative way?

My best wishes

[kevinarden]

I believe that is possible. You can create a mesh for every step, then use restart to start each step with the previous saved field variables. However the previous technique discussed is not limited to 2D, I have done it in 3D. The specific form is just a function of its mesh. The trajectory can be programmed into the sif using lau, matc, or a user function.

Perhaps you could post the first position as an example?

[raback]

Hi

Even remeshing with mmg might not be that far if you want to walk on the bleeding edge.

-Peter

[fjimenez]

Hi giulian,

You might be thinking on something like this:

animation.gif (555.75 KiB) Viewed 1089 times

You can easily replicate it if you use salome and dakota in the pipeline. You can change Salome for gmsh if you want, I prefer to use Salome for all my meshing tasks. I haven't been able to get good results with mortar and edge elements, I might be just missing some flags but have not find the right combination yet. The test cases run pretty nice but I get poor results whenever I use one of my meshes. Probably Peter could shed some light on this topic.

Quick question for Peter: can we use MMG with MagnetoDyanmics Solvers (2d/3D)? Is there a test case I can use as reference? I have tried MMG myself with both solvers (2d/3D) with no luck. I assume MMG+edge elements might not play along that well but I guess that a 2D case might be possible.

Cheers,

PS: Case files are here

[raback]

Hi

MMG is a remeshing library that can take desired mesh density field as input. This field may be generated by error indicators but those are available only for select equations - AV solver is currently not supported. More realistic would be a remeshing procedure where desired mesh density is provided by some other means.

-Peter

[giulian]

Dear All,

Thank you very much for your answers and your help. And Happy new Year!
What I wish to do is to calculate the EM field in a volume (air) where I have a metallic sphere "moving" inside it. Inside this volume there is also a metallic plate at rest. I also post a mesh example. Unfortunately I'm new at this kind of simulations and It's not particularly evident what would be the best approach.

Thank you very much again and I will dig in all your suggestions thoroughly.

My best regards