Can't use Post-Processing functions due to agglomeration files missing.

Chris T · March 14, 2023, 05:04

When running
chtMultiRegionFoam -postProcess -func wallHeatTransferCoeff -time 40 (also tried yPlus)
I get
--> FOAM FATAL ERROR:
cannot find file ".../constant/air/finalAgglom"

For my radiation model I use

Code:

runParallel -s air faceAgglomerate -region air -dict system/air/viewFactorsDict
runParallel -s air viewFactorsGen -region air

This is done after I used

Code:

runApplication decomposePar -allRegions -dict system/decomposeParDict

and essentially creates the finalAgglom file only in the processor files.

I did that because for some reason when I do the calculation for view factors and Face agglomerates first with

Code:

faceAgglomerate -region air -dict system/air/viewFactorsDict
viewFactorsGen -region air

and then decompose my case the finalAgglom file doesn't make it to the processor files.
as it can be seen from the error bellow when I try to run the case
--> FOAM FATAL ERROR:
[5] cannot find file ".../processor5/constant/air/finalAgglom"

Basically I need finalAgglom to both be present in the constant directory and the processor1/constant directory. In the former to be able to use post-processing utilities after reconstruction and the later to be able to run my solvers in parallel.

The obvious solution is to run the faceAgglomerate and viewFactorsGen utilities twice. Both in parallel to fill the process directories and in series to fill the constant directory. There are two problems with this approach though.
1. I do the computation twice. The one time is not even parallel.
2. I can't know if the finalAgglom file from the two processes are equivalent.

If anyone has a more elegant solution please let me know

The issue with the missing files while running viewFactor model in parallel is a known issue as docimented in running viewFactor model in parallel. In my case it also interferes with the use of post processing utilities.

Best,
Chris

Chris T · March 14, 2023, 05:14

I'm using OpenFoam v9 btw. Which makes things worse since there are no tutorials using the viewFactor radiation model present in this version. I had to look online for examples.

March 14, 2023, 05:04	Can't use Post-Processing functions due to agglomeration files missing.	#1
Chris T New Member Chris Join Date: Jan 2022 Posts: 22 Rep Power: 4	When running chtMultiRegionFoam -postProcess -func wallHeatTransferCoeff -time 40 (also tried yPlus) I get --> FOAM FATAL ERROR: cannot find file ".../constant/air/finalAgglom" For my radiation model I use Code: runParallel -s air faceAgglomerate -region air -dict system/air/viewFactorsDict runParallel -s air viewFactorsGen -region air This is done after I used Code: runApplication decomposePar -allRegions -dict system/decomposeParDict and essentially creates the finalAgglom file only in the processor files. I did that because for some reason when I do the calculation for view factors and Face agglomerates first with Code: faceAgglomerate -region air -dict system/air/viewFactorsDict viewFactorsGen -region air and then decompose my case the finalAgglom file doesn't make it to the processor files. as it can be seen from the error bellow when I try to run the case --> FOAM FATAL ERROR: [5] cannot find file ".../processor5/constant/air/finalAgglom" Basically I need finalAgglom to both be present in the constant directory and the processor1/constant directory. In the former to be able to use post-processing utilities after reconstruction and the later to be able to run my solvers in parallel. The obvious solution is to run the faceAgglomerate and viewFactorsGen utilities twice. Both in parallel to fill the process directories and in series to fill the constant directory. There are two problems with this approach though. 1. I do the computation twice. The one time is not even parallel. 2. I can't know if the finalAgglom file from the two processes are equivalent. If anyone has a more elegant solution please let me know The issue with the missing files while running viewFactor model in parallel is a known issue as docimented in running viewFactor model in parallel. In my case it also interferes with the use of post processing utilities. Best, Chris

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March 14, 2023, 05:14		#2
Chris T New Member Chris Join Date: Jan 2022 Posts: 22 Rep Power: 4	I'm using OpenFoam v9 btw. Which makes things worse since there are no tutorials using the viewFactor radiation model present in this version. I had to look online for examples.