|View Issue Details|
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0002759||OpenFOAM||[All Projects] Bug||public||2017-11-14 22:06||2017-11-28 23:13|
|Target Version||Fixed in Version|
|Summary||0002759: fvDOM with wedge patch gives inaccurate heat flux calculation|
|Description||I 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|
|Tags||chtMultiRegionSimpleFoam, fvDOM, Heat transfer, radiation|
|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|