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EP file need all elements?

Posted: 22 Oct 2010, 05:22
by shirazbj
Hi,

I am trying to output an EP file from my code. I have both solid elements and surface elements for my case. It is a 3D geometry, but only solved in 2D. Like a flow around a column in a channel.

Just wondering do I need to output all elements? Could I just output solid elements or surface elements for the animation?

Regards,

Cean

Re: EP file need all elements?

Posted: 22 Oct 2010, 11:06
by raback
Hi Cean

You can mask the dofs so that they are only saved there where some field variable is active. For the .ep file defined in the Simulation section use

Code: Select all

Post File Mask Variable = String varname
while for ResultOutputSolve in the Solver section say just

Code: Select all

Mask Variable = String varname
This should work with formats Vtu, Gmsh, and ElmerPost.

Just saving the bulk elements is not posisble, to my knowledge, but the boundary elements are usually not detrimental for performance.

-Peter

Re: EP file need all elements?

Posted: 22 Oct 2010, 13:49
by shirazbj
This is what I want to get.

But it is in VTK format. It only has value for inside solid elements for one time step.

I want to output in a single EP file which includes all time step data to animate the dam break process.

Re: EP file need all elements?

Posted: 30 Oct 2010, 14:13
by shirazbj
Hi Peter,

Sorry, I didn't understand what you said.

I have attached my EP file, it includes both the surface elements and inside solid elements. Because the values for

the surface element are all 0, it shows all BLUE. Though there are 3 solid elements that have value of 1, I can't

see through the surface. If I clip, It only shows a hollow space.

I tried to delete the surface elements, only keep the solid elements, but it shows nothing on the screen. "Color

Mesh" only shows the surface mesh. My value is at cell center. Maybe I need to get the value at vertex.

Regards,

Cean

Re: EP file need all elements?

Posted: 30 Oct 2010, 20:14
by raback
Hi Cean

Well, it seems that your problem is not to be selective on what you save but rather what you show. If your dof is zero at all boundaries you should use iso surfaces and clipping planes to access the internal features of your computation. Note also that in ElmerPost all dofs are nodal ones i.e. you do not have values defined element-wise. The nodal values are visualized using linear interpolation in between. This is inherent in ElmerPost and not likely to change. In Paraview, for example, you can have both point and cell values allowing discontinuities in the visalization. Is this also your wish? Most equations give continuous solutions (all solutions in standard nodal elements) so the alternative approach has not been that actively pursued.

-Peter

Re: EP file need all elements?

Posted: 01 Nov 2010, 05:47
by shirazbj
Ok, I need to get the nodal value from cell centered value.

Thanks.

Re: EP file need all elements?

Posted: 02 Nov 2010, 05:00
by shirazbj
Hi Peter,

Is it possible for ElmerPost to assign the cell center value to every nodes of the cell? It's not precise, but good for a quick look.

Regards,

Cena

Re: EP file need all elements?

Posted: 03 Nov 2010, 15:55
by shirazbj
I assigned the cell center value to every n
clipped one
clipped one
cut.gif (9.07 KiB) Viewed 3200 times
good one
good one
good.gif (9.67 KiB) Viewed 3200 times
odes of the cell in my code and finally got the right EP file.