Display Body Force

Post processing utility for Elmer
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Naorgk
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Joined: 19 Aug 2015, 13:40
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Display Body Force

Post by Naorgk » 19 Aug 2015, 15:13

Hello everyone,

I've recently started using Elmergui to solve magneto dynamic problems, for this I have defined a current density as a body force.
I was wondering if there is a way to display the body force in ElmerPost to see if it is defined correctly.

Thank you for your help!

mzenker
Posts: 1766
Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Display Body Force

Post by mzenker » 20 Aug 2015, 11:15

Hi,

as the current density is a vector, you either have to calculate its magnitude and display that one (you need to enter some math commands for that), or display it as vector - but I don't remember how that worked. There is a ElmerPost help which explains many things.
If all else fails, you can change the output file extension from .ep to .vtu in the sif file, rerun the simulation and use ParaView as postprocessor.

HTH,

Matthias

jay
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Joined: 05 Jun 2015, 12:46
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Re: Display Body Force

Post by jay » 27 Aug 2015, 18:14

hi Naorgk

If your problem is still not solved then try new release of Elmer. The current density that you define as body force can be seen in the post processing. Thanks to CSC team.

For eg. you can see the attached screen shots of my post processed results in paraview.
Attachments
current density_2.jpg
current density_2.jpg (64.21 KiB) Viewed 3597 times
current density1.jpg
current density1.jpg (35.92 KiB) Viewed 3597 times

jay
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Re: Display Body Force

Post by jay » 27 Aug 2015, 18:31

So with refence to my previous comment, I have some queries about the results obtained for current density.
For the model attached in my prvious comment I have used body force as:

Current Density 1 = Variable coordinate,
Real MATC "-(6.25e6)*tx(1)/sqrt((tx(1)*tx(1))+(tx(0)*tx(0)))"
Current Density 2 = Variable coordinate,
Real MATC "(6.25e6)*tx(0)/sqrt((tx(1)*tx(1))+(tx(0)*tx(0)))"

So here the absolute value is 6.25e6 A/m^2

Now according to post processed results, in one of clipped plan I can see in some patches of coil cross section, current densities are above 9E6 A/m^2.
So my question is paraview showing me absolute value or value of conponent of particular tangential vector of current in that place or current in the mesh element their.?

As per my understanding the for appied current, its direction in each element will be as shown in the attached image. So if i clip the model from some place, what quantity of current will paraview show me ?
Personally I wish to see absolute value of current which should be uniformly distributed over entire cross section of coil. How can it be acheived?
The simulation is carried out for static model.

I will be glad if some one can help me in understanding the nformation obtained in Paraview.

Thank you in advance

With Kindest Regards
jay panchal
Attachments
current direction in each first order element.jpg
current direction in each first order element.jpg (48.31 KiB) Viewed 3588 times

pavel
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Re: Display Body Force

Post by pavel » 01 Sep 2015, 03:48

Hi jay,

Have you tried to set keyword Discontinuous Galerkin = True as it is recommended in the Elmer Models Manual?

BR, Pavel

jay
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Re: Display Body Force

Post by jay » 01 Sep 2015, 11:01

pavel wrote:Hi jay,

Have you tried to set keyword Discontinuous Galerkin = True as it is recommended in the Elmer Models Manual?

BR, Pavel
Hi Pavel

Thank you so much for your reply.

I have not tried that key word. Actually this was new thing that I came accross. I checked the information in ElmerModel manual and it seems this keyword belongs to Bsolver for magnetic field in 2D case.
The case I am working at is 3D, so do I need to apply another solver section in my sif file and will take into consideration the discontinuty in 3D fields?

I have attached my sif file with this post for your reference. Can you please have look and provide your observations.

Thanking You
With Kindest regards
Jay
Attachments
case.sif
(3.37 KiB) Downloaded 131 times

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