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chtMultiRegionFoam heat transfer in CAD model

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Old   July 13, 2021, 06:00
Default chtMultiRegionFoam heat transfer in CAD model
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Sergey
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Hello!
I'm trying to use chtMultiRegionFoam solver water cooling calculation of the imported CAD models (in this case FreeCAD).
I've tested my OpenFOAM project with 2D GMSH model and it worked fine. Now, when I import FreeCAD model in STEP format and prepare it using GMSH I have the following problems:

there's no heat transfer between regions (with compressible::turbulentTemperatureCoupledBaffleMix ed boundary condition);
volumetric heat source (neither scalarSemiImplicitSource not scalarCodedSource) doesn't produce any heat.

Could you please look at my project and tell me, what's wrong with it?

PS, boundary types are defined in system/changeDictionaryDict, boundary conditions are defined in system/[region]/changeDictionaryDict, volumetric heat source is defined in constant/heater/fvOptions
PPS, sorry for not following the OpenFOAM scripting convention. One can run project by issuing command
Code:
./clean && ./configure && ./run && ./viewfoam
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Old   July 13, 2021, 07:23
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Domenico Lahaye
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Is the fluid domain gradually heating up with time?
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Old   July 13, 2021, 07:30
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Basic setup is this. I have a tungsten heater split into two parts: heating volume (called heated) and the rest of the tungsten part (called tungsten). I's enclosed in copper shell, which is cooled by a water stream. Heater supposed to gradually heat up while the water is cooling it down.
In short my goal is to optimize the geometry of the copper shell and determine the water consumption to cool down a heating tungsten target.
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Old   July 14, 2021, 06:52
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I was able to produce a minimal working example. Here I'm just testing for heat transfer in a solid cylinder (water is a placeholder). It seems that OpenFOAM does not account for boundary conditions when solving for temperature.



question3.zip
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Old   July 14, 2021, 09:23
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I thing I'm onto the source of the problem.
There are two problems here. The first problem is a duplication of the shared surfaces. They can be removed by adding the following line
Code:
BooleanFragments{ Volume{:}; Delete; }{}
to the GMSH script (http://geuz.org/pipermail/gmsh/2019/012855.html). Second problem is a sneaky one. GMSH does not respect length units of the imported step file. To convert your step file to meters add line
Code:
Mesh.ScalingFactor=0.001;
to the GMSH script (Gmsh units?).

Last edited by seregaxvm; July 14, 2021 at 09:23. Reason: Remove attachments
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Old   July 20, 2021, 17:45
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For the sake of completeness, here's a working project watercooling.zip
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Old   August 4, 2021, 08:57
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It's better to use
Code:
Geometry.OCCTargetUnit = "M";
instead of

Code:
Mesh.ScalingFactor=0.001;
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chtmultiregionfoam, freecad, gmsh, heat exchange, heat sources

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