2017-12-15 23:41 GMT

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IDProjectCategoryView StatusLast Update
0002759OpenFOAM[All Projects] Bugpublic2017-11-28 23:13
Reporterjaydeep 
Assigned To 
PrioritynormalSeveritymajorReproducibilityalways
StatusnewResolutionopen 
Product Versiondev 
Target VersionFixed in Version 
Summary0002759: fvDOM with wedge patch gives inaccurate heat flux calculation
DescriptionI tried a validation problem with fvDOM on axisymmetric case. The example case is attached.

Radiative analytical heat flux from "hot" wall comes out to 260.9 kW/m2.

Axisymmetric test case under-predicts the heat flux (15% error) (wedge patch).

I tried alternate approach with symmetry patches and semi-circular model with extrusion model "sector" instead of "wedge". With this approach I get values closer to analytical (about 2% error).

This problem exacerbates with higher model complexity. For more complex problems I'm observing this deviation > 25%.

I am not sure what could be a fix but I suspect the solution might lie in how fvDOM deals with wedge patches:
fvDOM uses strategy based on nSolutionD as,
if (nSolutionD == 2) ...
if (nSolutionD == 3) ...

from polyMesh::nsolutionD, for wedge type geometry, nSolutionD is returned as 3. Hence the radiation problem is treated as 3D - requiring both nTheta and nPhi in fvDOM. As a ramification of this - solver crashes if you set nTheta =0. The wedge patch does not participate in radiation, yet, fvDOM solves for transport across them since nTheta !=0; leading to loss of rays??

Hence, in the validation case attached, there could be some ray loss? I am not sure if I am putting it in right words.
Steps To Reproduce./Allrun
TagschtMultiRegionSimpleFoam, fvDOM, Heat transfer, radiation
Attached Files
  • zip file icon case.zip (12,745 bytes) 2017-11-14 22:06

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-Issue History
Date Modified Username Field Change
2017-11-14 22:06 jaydeep New Issue
2017-11-14 22:06 jaydeep File Added: case.zip
2017-11-14 22:06 jaydeep Tag Attached: chtMultiRegionSimpleFoam
2017-11-14 22:06 jaydeep Tag Attached: Heat transfer
2017-11-14 22:06 jaydeep Tag Attached: radiation
2017-11-14 22:06 jaydeep Tag Attached: fvDOM
2017-11-28 23:13 wyldckat Product Version => dev
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