Write field data at a few specific timesteps

gary7 · January 9, 2014, 17:45

Hi All,

Is it possible to control the writing of the filed data happens at some specific timesteps which are not necessarily a multiple of "writingInterval"? Let's say I want the data to be written only at timesteps = 10, 17, 43 and 71. Right now I have to write data out every timestep in order to obtain field at these timesteps.

How can I write data only at the mentioned timesteps?

Cheers,
Kasra.

KateEisenhower · October 21, 2016, 08:51

Hi Kasra,

have you found any answer to this question? Of course one could write a shell-script which reads the OpenFOAM output and changes the controlDict at the appropriate time, but that isn't very elegant.

Best regards,

Kate

gary7 · October 21, 2016, 14:40

Hi Kate,

I used a quick hack to do it. It is not the best way to do it but it does the job:

Code:

if
(
   mag(runTime.value() - runTime.deltaT().value() * 10) < SMALL
)
{
    runTime.writeNow();
}

This will write out the results at 10th timestep.

Cheers,
Kasra.

KateEisenhower · October 24, 2016, 07:12

Hi Kasra,

thanks for your response. This works only for a fixed timestep, right?

Kate

gary7 · October 24, 2016, 17:42

That's right. You can write the results at specific timesteps, you can add more timesteps using "or" (||) operator. However, the clean and robust way of doing it is defining an IOdictionary and list the required timesteps in there and use those instead of hard coding the timesteps right into the code.

Brandani · March 11, 2020, 13:31

Hi! Do you happen to know how to use the IO dictionary to make your simulation write out user-specified times?

January 9, 2014, 17:45	Write field data at a few specific timesteps	#1
gary7 Member Kasra Join Date: Jun 2010 Location: USA Posts: 44 Rep Power: 16	Hi All, Is it possible to control the writing of the filed data happens at some specific timesteps which are not necessarily a multiple of "writingInterval"? Let's say I want the data to be written only at timesteps = 10, 17, 43 and 71. Right now I have to write data out every timestep in order to obtain field at these timesteps. How can I write data only at the mentioned timesteps? Cheers, Kasra. Last edited by gary7; January 10, 2014 at 01:43.

October 21, 2016, 14:40		#3
gary7 Member Kasra Join Date: Jun 2010 Location: USA Posts: 44 Rep Power: 16	Hi Kate, I used a quick hack to do it. It is not the best way to do it but it does the job: Code: if ( mag(runTime.value() - runTime.deltaT().value() * 10) < SMALL ) { runTime.writeNow(); } This will write out the results at 10th timestep. Cheers, Kasra.

October 24, 2016, 17:42		#5
gary7 Member Kasra Join Date: Jun 2010 Location: USA Posts: 44 Rep Power: 16	That's right. You can write the results at specific timesteps, you can add more timesteps using "or" (\|\|) operator. However, the clean and robust way of doing it is defining an IOdictionary and list the required timesteps in there and use those instead of hard coding the timesteps right into the code. KateEisenhower and reza.saghi like this.

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October 21, 2016, 08:51		#2
KateEisenhower Senior Member Join Date: Mar 2015 Posts: 250 Rep Power: 12	Hi Kasra, have you found any answer to this question? Of course one could write a shell-script which reads the OpenFOAM output and changes the controlDict at the appropriate time, but that isn't very elegant. Best regards, Kate

October 24, 2016, 07:12		#4
KateEisenhower Senior Member Join Date: Mar 2015 Posts: 250 Rep Power: 12	Hi Kasra, thanks for your response. This works only for a fixed timestep, right? Kate

March 11, 2020, 13:31		#6
Brandani New Member Mark Join Date: Oct 2018 Posts: 18 Rep Power: 8	Hi! Do you happen to know how to use the IO dictionary to make your simulation write out user-specified times?