"Constraint Body Heat Source" implemented yet?
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"Constraint Body Heat Source" implemented yet?
Thanks for all the great work in getting FreeCAD 0.17 out, it is becoming truly useful
A simple question, attempting to edit a "Constraint Body Heat Source" object does not bring up the expected selection panel therefore I assume that actually creating a body heat source has not yet been implemented, or am I missing something?
Thanks
Stair
OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13522 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 3bb5ff4e70c0c526f2d9dd69b1004155b2f527f2
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedKingdom (en_GB)
A simple question, attempting to edit a "Constraint Body Heat Source" object does not bring up the expected selection panel therefore I assume that actually creating a body heat source has not yet been implemented, or am I missing something?
Thanks
Stair
OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13522 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 3bb5ff4e70c0c526f2d9dd69b1004155b2f527f2
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedKingdom (en_GB)
Re: "Constraint Body Heat Source" implemented yet?
AFAIK ther is jut no task panel, input the heat source in the property editor. It is just a nomber.
Re: "Constraint Body Heat Source" implemented yet?
Thanks for the reply.
In that case I don't understand the function of Constraint Body Heat Source, I thought it is the heat sourced from a solid body, in Elmer terms Body Forces:Heat Source, so I am expecting 2 parameters, the ID of the solid and the the heat in W/m^3 or W/kg
Since there is nothing yet in the Wiki please could you explain the how to use this constraint, if the number entered is the heat source how do you define what it refers to
Thanks
Stair
In that case I don't understand the function of Constraint Body Heat Source, I thought it is the heat sourced from a solid body, in Elmer terms Body Forces:Heat Source, so I am expecting 2 parameters, the ID of the solid and the the heat in W/m^3 or W/kg
Since there is nothing yet in the Wiki please could you explain the how to use this constraint, if the number entered is the heat source how do you define what it refers to
Thanks
Stair
Re: "Constraint Body Heat Source" implemented yet?
he should know!HoWil wrote:
Re: "Constraint Body Heat Source" implemented yet?
Hi Bernd, Hi stair,
BodyHeatSource was implemented during last GSoC (see also https://forum.freecadweb.org/viewtopic. ... ux#p188021) but it seams to be broken. I remember discussions with Markus about dividing the flux value by the density of the domain because of the way the flux is handled in Elmer.
I have built a simple model where I wanted to use this constraint. If I include the constraint into my analysis than the sif-writer does not start! If I exclude it and insert e.g. a HeatFlux onto one surface, everything works fine.
So I think simply this constraint is not working and blocking somehow the execution of the complete analysis.
BR,
HoWil
Attached you find my model including a Heatflux via a surface and the not working BodyHeatSource constraint which is excluded from the analysis and can be drag-n-drop inserted into the analysis.
- Attachments
-
- FC_heat_flux_example.fcstd
- (230.59 KiB) Downloaded 91 times
Re: "Constraint Body Heat Source" implemented yet?
There is no task panel implemented at all, see https://github.com/FreeCAD/FreeCAD/blob ... tSource.py
The BodyHeatSource object defines a property "HeatSource" : https://github.com/FreeCAD/FreeCAD/blob ... rce.py#L39
but the elmer writer tries to access a property "HeatFlux" : https://github.com/FreeCAD/FreeCAD/blob ... er.py#L268 which does not exist in the BodyHeatSource object.
This could be easily fixed by replacing HeatFlux with HeatSource (which I will include in my next PR, https://github.com/berndhahnebach/FreeC ... aa9f301b08 ), but I do neither know about the unit nor about the correct further handling of elmer.
bernd
Re: "Constraint Body Heat Source" implemented yet?
IMHO, the units should be correct too. https://github.com/berndhahnebach/FreeC ... 1c63550c67
@wlifried, would it be possible to check if your example gives reasonable results? You could fix your elmer writer temporary yourself to test?
@wlifried, would it be possible to check if your example gives reasonable results? You could fix your elmer writer temporary yourself to test?
Re: "Constraint Body Heat Source" implemented yet?
I changed it locally and the simulation runs now.
The unit for HeatSource in writer.py is "W/kg" which suggests that one has to divide the introduced specific heat energy given in W/m³ by the density of the domain given in kg/m³.
Right now I do not have an idea how to test the constraint, since the HeatSource is applied to the complete simulation domain. I guess there was a reason why Markus did not add a domain-selection to this constraint.
BR,
HoWil
Re: "Constraint Body Heat Source" implemented yet?
@Bernd
What do you think, should we introduce a domain selection for the heat source?
I manually disabled the heat-source (body-force) in the exported .sif and I get qualitatively resonable results... Please see the attached screenshot where the inner domain is heated... @stair,
I will try to rebuild the original Elmer tutorial model from over here http://www.nic.funet.fi/index/elmer/doc ... orials.pdf (p4..."Heat equation – Temperature field of a solid object").
BR,
HoWil
Re: "Constraint Body Heat Source" implemented yet?
adding the References property to the object and the selection widget to the objects task panel is simple, I could do this. But who does the elmer writer implementation? I have no glue how this would work, and not a strong interest to spend much time on this either .