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SimpleFoam as laminar solver

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Old   March 24, 2006, 05:48
Default Hi, as simpleFoam is a stea
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Anja Stretz
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Hi,

as simpleFoam is a steady-state solver, the defined "timestep" is an iteration counter. Does that mean, that the "endTime" is the max number of iterations? And why is then within each timestep an iteration of p (in my case only in the beginning of the calculation, problem follows)

I want to calculate u and p but:
Time = 999
AMG: Solving for p, Initial residual = 1.02579e-06, Final residual = 2.76786e-07, No Iterations 1
time step continuity errors : sum local = 6.13966e-06, global = 5.96414e-08, cumulative = 0.000117451
ExecutionTime = 9411.37 s

Time = 1000
time step continuity errors : sum local = 1.01213e-05, global = -4.50328e-08, cumulative = 0.000117406
ExecutionTime = 9419.22 s


Thanks a lot for your help!
Anja
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Old   March 24, 2006, 05:59
Default Yes, endTime is the max iterat
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Hrvoje Jasak
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Yes, endTime is the max iteration count. However, based on the snippet of the log file, you run has converged a long time ago. What you are seeing are the oscillations in the pressure due to round-off.

Have a look at the point where the momentum equation was solved last - this is where you should have stopped the solver. Note: the convergence checks in simpleFoam may be somewhat different to what you're used to: for example, if you want to converge the global residual to 1e-6, you should specify the linear solver convergence to be lower. Otherwise, as you approach the global convergence tolerance, the solver stops doing the work and nothing much happens. I personally always check the global convergence by hand (well, eyes) :-)

Enjoy,

Hrv
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Old   March 24, 2006, 07:20
Default Well, this is what I was using
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Anja Stretz
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Well, this is what I was using:
p AMG 1e-06 0 100;
U BICCG 1e-05 0.1;

What would you change?

How do you check the global convergence?

THANKS!
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Old   April 5, 2007, 09:28
Default Hi world, I am in the same
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Hi world,

I am in the same situation like Anja:
I want my computation to stop when it reachs the criterium of convergence that I precise (the solver tolerance in system/fvSolution file, isn't it?), and not in function an arbitrary number of iterations (endtime, in system/controlDict in file).

Can somebody help me to do this, please?

Thanks in advance,

Lam
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