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-   -   HELP TIME on FLUENT (http://www.cfd-online.com/Forums/fluent/101736-help-time-fluent.html)

 slimmsk May 12, 2012 17:26

HELP TIME on FLUENT

hello,

I simulated a fluid flow in a straight pipe with ANSYS Fluent :

Inlet velocity : 0.116 m/s
Outlet pressure 400 Pa with mass flow rate 0.063 kg/s

Time step size: 60 seconds
Number of time step: 5
Number of iterations / time step: 300

I find the same result
I noticed that the solver resolves five blocks of 300 iterations each time, is it recalculates every time?

60 seconds is enough or must I fix a few minutes

thank you very much

 LuckyTran May 12, 2012 18:37

Quote:
 Originally Posted by slimmsk (Post 360743) hello, I simulated a fluid flow in a straight pipe with ANSYS Fluent : Inlet velocity : 0.116 m/s Outlet pressure 400 Pa with mass flow rate 0.063 kg/s Time step size: 60 seconds Number of time step: 5 Number of iterations / time step: 300 I find the same result I noticed that the solver resolves five blocks of 300 iterations each time, is it recalculates every time? 60 seconds is enough or must I fix a few minutes thank you very much
it will solve 300 iterations at the current time, then move to the next time-step and do another 300 iterations until 5 time-steps have been solved.

isn't this a steady problem? none of your boundary conditions appear to be transient, your simulation will be steady even if you run a transient simulation.

 slimmsk May 13, 2012 05:04

2 Attachment(s)
hello,

I try to simulate flow between two cylinders.

Normally I should get a constant velocity profile along the length (figure 1).
Attachment 13094
But, I found an acceleration along the entire length of the cylinder (figure 2).
Attachment 13095
Change speed / length axis> 0

normally it must be = 0

I can not find the trick. Is that it's normal?

thank you

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