Error writing monitor points to file

selvam2487 · December 11, 2015, 05:59

Dear Friends,

I am performing LES of T-junction mixing flows and have placed around 300 monitor points within my computational domain. Time step used in LES is 0.2 ms and the physical time presently simulated is around 37 seconds (approx. 183000 iterations).
Over the past week I noticed that the monitor points are not written to the results file due to their size exceeding 2 GB of memory. I have attached a pdf of the error and a clip of contenets inside the .dir folder created during LES the run along with this thread. I am currently using around 240 processors to perform the LES and the computational grid has close to 7 million nodes.
I would welcome your suggestions as to how to fix this issue? Should I use more processors or is there any alternate way to fix this problem. Thanks for you help in advance.

Regards,
Karthick

ghorrocks · December 11, 2015, 06:53

Are you using 64 bit CFX on a 64 bit OS?

Other than that I cannot suggest much except to use less monitor points, or to output less data at the monitor points. All the nodes save the monitor point data in the single file so more partitions will not help. Also you could remove some values that can be calculated as post-processing, eg if you output both pressure and absolute pressure, you could reduce that to just pressure and calculate absolute pressure as post processing.

Oh yes, and if you are confident about your convergence you could remove the convergence monitors from the file, imbalances, boundary integrals and all the other things in there by default which you might not need.

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December 11, 2015, 06:53		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	Are you using 64 bit CFX on a 64 bit OS? Other than that I cannot suggest much except to use less monitor points, or to output less data at the monitor points. All the nodes save the monitor point data in the single file so more partitions will not help. Also you could remove some values that can be calculated as post-processing, eg if you output both pressure and absolute pressure, you could reduce that to just pressure and calculate absolute pressure as post processing. Oh yes, and if you are confident about your convergence you could remove the convergence monitors from the file, imbalances, boundary integrals and all the other things in there by default which you might not need.