Output of Temperature in a selected Point

[FDS_User]

All,

I'm new to Elmer and have the follwing question.
I successfully run a transient simulation of heat transfer. The visual output seems to be OK but I need temperature values inside my solid. I only have the coordinates of some points in meter (say x= 1, y= 2, z =3) and I need the output of the temperature after every timestep at this selected point. I tried SaveScalars, but I'm not able to specify a single coordinate in meters.

Thanks for your help.
Christian

[alibrandi]

Maybe you can try this solution: in SaveScalars you can specify in Save Points the points (node numbers) that you need. You can check the node numbers directly in elmer GUI or in the mesh.nodes file (you can open it with notepad).
Elmer will create a file with the evolution of your variable for each timestep for the node that you chose. That file will also show you the coordinates of the selected node.
I had the same problem and I hope that this solution could be helpful also for you.
Alibran

[raback]

Hi

In SaveScalars there is also the keyword "Save Coordinates" that as arguments expects the coordinates of the point you're interested in. By default a nearest point is used but you can say "Exact Coordinates = True" so that the value will be computed with appropriate weights from the nodal values within the element in question. Formally

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Save Coordinates(1,3) =  1.0 2.0 3.0
Exact Coordinates = True

For more info look at Models Manual.

A recent update is that the SaveScalars should be in most parts working also in parallel when you say "Parallel Reduce = Logical True".

-Peter

[FDS_User]

All,

thanks for your help. It works like it should.
For all who have the same problem, here is the solver I used for a 2Dim problem.

Code: Select all

Solver 2
  Procedure = "SaveData" "SaveScalars"
  Exec solver = after timestep
  FileName = "file.dat"
  Save Coordinates(1,2) = 0.05 0.035
  Exact Coordinates = True
  Variable 1 = Time
  Variable 2 = Temperature
End

Regards,
Christian

[menwai]

All,

All,

How can I copy the code to the elmer?
Is it that I copy the code to the text generated from the SIF and save it to another file?

Regards,
Men

thanks for your help. It works like it should.
For all who have the same problem, here is the solver I used for a 2Dim problem.
CODE: SELECT ALL
Solver 2
Procedure = "SaveData" "SaveScalars"
Exec solver = after timestep
FileName = "file.dat"
Save Coordinates(1,2) = 0.05 0.035
Exact Coordinates = True
Variable 1 = Time
Variable 2 = Temperature
End

Regards,
Christian

[raback]

How can I copy the code to the elmer?

Open the *.sif file with you favorate text editor and copy-paste the section with the next free Solver index. In Windows many use notepad++ and in Unix you never go wrong with emacs. Note that once you have edited the *.sif file you cannot go back to using the ElmerGUI.

You can also add the menu structure of SaveScalars in the ElmerGUI by selecting
File -> Definitions -> Append -> $ELMER_HOME/bin/edf_extra/savescalars.xml

-Peter

[menwai]

thx for the reply.
I alrdy able to generate the point but i would like to ask if I wan to generate the velocity_x for the specific point. what should I written in the variable column?

Another issue is regarding the "saveline". After i save the file in .dat and open using note pad. A series of data appear with no label and i am not sure which is velocity_x, velocity_y. How can I interpret the data?

Regards,
men wai

[raback]

1) Just don't specific any variables and you get them all
2) Both SaveScalars and SaveLine should output a .names file that should explain what you have

[menwai]

For SaveScalars and saveline interface,
In the "Edit Solver Settings" interface, I try to key in the column for save coordinate = 1 2 which means at point of (1,2) but the solver read at the point of (x,y)=(1,0) rather than point (1,2). Why?

Another thing is I need to save the savescalars in the same equation with the naive stokes equation or can i create a new equation just for savescalars and run together with the naive stokes?

regards,
men wai

[raback]

Hi

ElmerGUI lacks the possibility to give size as part of the keyword in style

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Gravity(4) = 0 -1 0 9.81

Instead you have to do as

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Gravity = Size 4; 0 -1 0 9.81

-Peter