preventing of writing of excess folders

immortality · July 29, 2013, 09:40

in time folders some as look excess folders like ddt0(rho),k_0,ddt0(rho,U),...
most of them with a 0 suffix are written in time folders.
what do they for solver and how can prevent writing them in time folders due to no need to them in post processing.

Bernhard · July 29, 2013, 09:45

As far as I know, they are needed for restarting, depending on your time-integration scheme, as it stores the previous time step.

immortality · July 29, 2013, 10:21

thanks,then its because of crankNicolson I have chosen as time scheme.

Lieven · July 29, 2013, 10:56

Hi Ehsan,

That is exactly the reason. If you would take Euler you won't get those files. If you think about it, it makes perfectly sense that 2 previous time steps to restart a second order time integration scheme.

If you would write the output after every iteration, you will see that the "U_0" is exactly the same as the "U" file of the previous time step.

Cheers,

Lieven

July 29, 2013, 09:40	preventing of writing of excess folders	#1
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 26	in time folders some as look excess folders like ddt0(rho),k_0,ddt0(rho,U),... most of them with a 0 suffix are written in time folders. what do they for solver and how can prevent writing them in time folders due to no need to them in post processing. __________________ Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked.

July 29, 2013, 10:21		#3
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 26	thanks,then its because of crankNicolson I have chosen as time scheme. __________________ Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked.

July 29, 2013, 10:56		#4
Lieven Senior Member Lieven Join Date: Dec 2011 Location: Leuven, Belgium Posts: 299 Rep Power: 22	Hi Ehsan, That is exactly the reason. If you would take Euler you won't get those files. If you think about it, it makes perfectly sense that 2 previous time steps to restart a second order time integration scheme. If you would write the output after every iteration, you will see that the "U_0" is exactly the same as the "U" file of the previous time step. Cheers, Lieven immortality likes this.

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July 29, 2013, 09:45		#2
Bernhard Senior Member Bernhard Join Date: Sep 2009 Location: Delft Posts: 790 Rep Power: 21	As far as I know, they are needed for restarting, depending on your time-integration scheme, as it stores the previous time step.