Axi Symmetric BC for heat solver

Numerical methods and mathematical models of Elmer
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AlfredBerger
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Axi Symmetric BC for heat solver

Post by AlfredBerger »

Dear Sirs,

I still have problems in understanding how to adapt the BC for axi symmetry:
In regard to radiation: As the BC cannot be different to 3D case, do I need to change the material properties to get correct heat flux ?
In regard to heat flux: (specifically with heat transfer coefficient): Do I need to change the transfer coefficient or do I need to change also the material properties to get correct heat flux ?

kind regards,
AlfredBerger
raback
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Re: Axi Symmetric BC for heat solver

Post by raback »

Hi

All units and BCs can be the same.

How do you obtain your heat flux. Distributed flux in W/m^2 or nodal flux in W?

The flux per area should be the same, the flux per node (f) must probably follows

\sum f_3d = 2*PI \sum f_2d

-Peter
AlfredBerger
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Re: Axi Symmetric BC for heat solver

Post by AlfredBerger »

Hallo Peter,

Thank you for your answer. If I understand you correctly, I can keep the same BC values: i.e. the heat transfer coefficient does not need to be changed when switching from 3D to axi symmetric 2D.

What I did so far: I did what I learnt from your various replies in this forum:
The x-axis is the axis of rotation for axi symmetric coordinate system. "Temperature load" is a nodal quantity in Watt, so is the sum. I summed up the values on the given boundary to calculate the total fluxes with this solver:
Solver 2
Procedure = "SaveData" "SaveScalars"  
  Filename = normalflux.dat
  Operator 1 = boundary sum
  Variable 1 = Temperature Loads
End

So there must be any inconsistency on my end. I will look further into it.

By the way: thank you very much for the excellent program and your always clear and fast reponses.
Alfred.
AlfredBerger
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Re: Axi Symmetric BC for heat solver

Post by AlfredBerger »

Hallo Peter,

Sorry for all the issue at all: it was a fault I had in my data transfer from the elmer output text file to spreadsheet (had an issue with libreoffice upgrade that mixed my values up). So Elmer did excatly what what one would expect. Sorry for causing inconvenience to answering.

kind regards,
Alfred.
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