How to have .RES files at every time-step

MFiX How to
#1

**I had a question regarding the .RES files. **
How to make .RES files at every ‘dt’?

Sometimes when simulations crashes prematurely. I generally try to restart it from the last saved point using the ‘RESTART_1’ option which uses the last saved data from the .RES file.

However, I was wondering if we can restart from sometime before that. For example, if it failed at 27 s and it was saved at 26 s, it will restart from 26 s. But can I restart the MFIX solver from say 20 s?

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#2

You can save a series of restart files at regular intervals. In Output>Basic, set res_backup_dt to say 1s and res_backups = 10. and it will save a rotating series of 10 restart files every 1 seconds. Here if the run failed at time=26.9 seconds, you could restart from time=17 to 26 seconds. You would need to manually copy and rename the restart file to [RUN_NAME].RES. Please note that it appears the labels in the GUI are swapped so “Restart backup count” should be “Restart backup interval” and vice versa.

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#3

So if I understand correctly, if the simulation crashed at say 27 s, and I have the 10 files (17 to 27s), I can rename the file of choice (say 20s) to RUN_NAME.RES and the choose ‘RESTART_1’ option in .MFX file and then run it?

#4

Correct, there will be a series of files in the BACKUP_RES folder, named RUN_NAME.RES01, RUN_NAME.RES02 etc and you will need to rename one of them and put it in the project directory before doing the RESTART_1.

#5

Got it. Let me try this and get back to you

#6

Dear Dr. Dietiker,

Is there a way to change this directly from the .MFX file in notepad ?

#7

No, this is a manual step that cannot be done through the .mfx file.

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