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Problem in restarting the run #34

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anikm21 opened this issue Aug 26, 2022 · 13 comments
Open

Problem in restarting the run #34

anikm21 opened this issue Aug 26, 2022 · 13 comments

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@anikm21
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anikm21 commented Aug 26, 2022

The restart file is being written according to the WALL CLOCK MAXIMUM TIME or, TOTAL SIMULATION TIME. It cannot be written according to the restart rate.
And the more important problem is that when I am restarting my run, it diverges at the first step calculating a very high value of timestep. Please reply me soon. I am adding the history file.
history.txt
@TakisCFD
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Make sure that the correct flags are used when restarting from a RESTART file

@anikm21
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anikm21 commented Oct 4, 2022 via email

@anikm21
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anikm21 commented Oct 4, 2022 via email

@qhma
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qhma commented Dec 11, 2022

I have the same question when I am restarting my run, it diverges at the first step calculating a very high value of timestep when I run multispeices Euler equation. Please reply me how to fix the problem.

@TakisCFD
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You will need to ensure that :

  1. the MULTISPECIES.DAT file is present in your simulation directory
  2. the RESTART.DAT file is present in your simulation directory
  3. the flags selected for the restart file are correct (such as restarting from steady or unsteady simulation, turbulent or non-turbulent)
  4. the types of equations solved should be -1
  5. the time advancement method should be explicit such as Runge-Kutta3

Hope this helps.

@falcaoceg
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falcaoceg commented Jan 16, 2023 •
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I am sorry to bother you guys again with the same issue, but I'm having the same problem and I would like to know about your solutions for this problem. I see some of you posted that the problem is solved... My simulation is very simple, single component, non-turbulent, unsteady RK2, N-S (all flags are according to it).

I run the simulation, the restart.dat file is generated at the end of the simulation. (not at xxx iterations :/ ).

When I simply run it again in order to restart it, the simulation stops because the simulation "end time" is reached no matter what time limit I impose, of course, the simulation is probably blowing up.

Thanks for your attention.

@TakisCFD
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TakisCFD commented Jan 17, 2023 via email

@falcaoceg
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falcaoceg commented Jan 17, 2023 via email

@TakisCFD
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Post your ucns3d.dat file and I will indicate what could be wrong

@falcaoceg
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UCNS3D.txt

(I changed the extension to *.txt only to upload here)

@TakisCFD
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CFL should be less than one since it might crash otherwise.

Check
Running the same setup for time stepping option 3 until I check that it might be a bug associated with RK2

@falcaoceg
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CFL should be less than one since it might crash otherwise.

Check Running the same setup for time stepping option 3 until I check that it might be a bug associated with RK2

Ok, the RK3 test I already performed but I'll do it again. I am running with this time step for a while now, but i will decrease it in order to verify. Appreciate your advices.

@sidkamat
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Thank you. Problem is fixed.
…
On Tue, 4 Oct 2022 at 09:49, Anik Mandal @.> wrote: May you suggest me how I can make sure that the correct flags are used? Because when I am restarting my job I only keep the restart file in the directory. On Fri, 23 Sept 2022 at 20:30, Takis Tsoutsanis @.> wrote: > Make sure that the correct flags are used when restarting from a RESTART > file > > — > Reply to this email directly, view it on GitHub > <#34 (comment)>, > or unsubscribe > https://github.com/notifications/unsubscribe-auth/AZL6LOSKIUJGSUJJHZDPSRDV7XAX7ANCNFSM57XJUYMQ > . > You are receiving this because you authored the thread.Message ID: > @.***> >

Hi. Can you tell me how you solved the code diverging on the first time step?

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5 participants
@sidkamat @TakisCFD @anikm21 @falcaoceg @qhma