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dkusmer
Posts: 25
Registered: ‎07-25-2011
Accepted Solution

why is the transient analysis only 10 seconds when it should be 40?

120 Views, 3 Replies
06-06-2013 07:51 AM

According to the CFD manual for transient analysis, the time step size is always in seconds. Therefore if I choose a time step size of 0.5 (seconds) and time steps to run as 80, the total amount of time should be 40 seconds, but analysis says 10 seconds (see attached png file). What am I missing here?

 

Thanks for your help, Dan

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Active Contributor
kabindrabhattarai
Posts: 26
Registered: ‎06-06-2013

Re: why is the transient analysis only 10 seconds when it should be 40?

06-06-2013 10:38 AM in reply to: dkusmer

I have faced similar probelm before. Is your intelligent solution control turned on? If yes, you may have to turn it off. The software may be calculating the time step it needs with that option turned on. Hope it helps.

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apolo.vanderberg
Posts: 290
Registered: ‎08-31-2011

Re: why is the transient analysis only 10 seconds when it should be 40?

06-06-2013 12:34 PM in reply to: kabindrabhattarai

That is correct

If Solution Control is enabled for transient runs the value listed on the Solve dialog will be the maximum (upper limit) for the timestep. From the solution control can adjust it smaller as needed to try and maintain stability.

Turn off solution control and we will march forward at the specified interval

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Contributor
dkusmer
Posts: 25
Registered: ‎07-25-2011

Re: why is the transient analysis only 10 seconds when it should be 40?

06-07-2013 07:33 AM in reply to: apolo.vanderberg

Kabindrabhattarai/Apolo,

 

Thank you both for your responses. I did have the intelligent solution control turned on. When I turned it off the duration time came out as predicted.

 

Thanks, Dan

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