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-   -   Steady and unsteady solves (http://www.cfd-online.com/Forums/fluent/49637-steady-unsteady-solves.html)

kospan October 28, 2008 06:00

Steady and unsteady solves
 
Hi. Can someone explain me how operate the steady-method solving and the unsteady? With other words, if we have a unsteady physical model (such as the most of physical problems) and we try to solute it with steady method, what will be the result? It must try ,first of all, to solute the broblem, with unsteady-method and while we see that the flow dosnt change, after we go to solute with steady flow?


JB October 28, 2008 08:57

Re: Steady and unsteady solves
 
From what I know, if you try to solve an unsteady problem with the steady-state solver, your solution might oscillate, as the solver will have problems trying to find a steady solution to a naturally unsteady problem.

I hope this helps /JB

kospan October 28, 2008 09:02

Re: Steady and unsteady solves
 
And with iteration number what happen? If i try to use a steady state where it affect, the solution, the diference number of iteration?

JB October 28, 2008 09:15

Re: Steady and unsteady solves
 
well if you plot your residuals and some kind of physical quantity representative of your problem, you might observe a periodic pattern. That means no matter how long (# of iterations) you run the simulation, it may never stabilize to a clean, 'steady' solution.


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