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Problems with adjustable timestep control and maxCo Number |
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November 18, 2008, 06:46 |
Hi all,
I'm using OF 1.5 an
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#1 |
Senior Member
Wolfgang Heydlauff
Join Date: Mar 2009
Location: Germany
Posts: 136
Rep Power: 21 |
Hi all,
I'm using OF 1.5 an try to make a turbFoam simulation run with adjustable Timestep control. But it doesn't work. the solver always keeps the preset deltaT. NO adjustment is done at all!! As I read in this forum ( http://www.cfd-online.com/cgi-bin/Op...cus/discus.cgi ) to make it work I have to change my turboFoam.C. But by recompiling it there appears an error: ------------------------- .../setInitialDeltaT.H: In function 'int main(int, char**)': .../setInitialDeltaT.H36: error 'CoNum was not declared in this scope turbFoam wurde nicht aktualisiert ------------------------- How can I correct the missing declaration? Or should this work in OF1.5 already rigth? If so, what do I have to change or adjust and in what file? Thanks a lot. |
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November 18, 2008, 07:21 |
in turbFoam.C
After:
# inc
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#2 |
Super Moderator
Niklas Nordin
Join Date: Mar 2009
Location: Stockholm, Sweden
Posts: 693
Rep Power: 29 |
in turbFoam.C
After: # include "initContinuityErrs.H" add this: # include "readTimeControls.H" and after: # include "CourantNo.H" add this: # include "setDeltaT.H" and run wmake. in system/controlDict add these lines. adjustTimeStep on; maxCo 0.3; |
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November 18, 2008, 08:55 |
Thank you. This solved it fina
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#3 |
Senior Member
Wolfgang Heydlauff
Join Date: Mar 2009
Location: Germany
Posts: 136
Rep Power: 21 |
Thank you. This solved it finally!!
As a conclution for all others: My turbFoam.C now looks like this: . . . int main(int argc, char *argv[]) { # include "setRootCase.H" # include "createTime.H" # include "createMesh.H" # include "createFields.H" # include "initContinuityErrs.H" # include "CourantNo.H" # include "readTimeControls.H" # include "setInitialDeltaT.H" // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Info<< "\nStarting time loop\n" << endl; for (runTime++; !runTime.end(); runTime++) { Info<< "Time = " << runTime.timeName() << nl << endl; # include "readTimeControls.H" # include "readPISOControls.H" # include "CourantNo.H" # include "setDeltaT.H" // Pressure-velocity PISO corrector . . . . My controlDict has the following lines attached ======================= . . adjustTimeStep yes; maxCo 5; maxDeltaT 0.01; . . . ================================= after that I did "wclean" and "wmake" inside the ../incompressible/turbFoam/ directory. Finally it works. |
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June 18, 2009, 14:00 |
courant number bigger in icoFoam
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#4 | |
Member
xianghong wu
Join Date: Mar 2009
Posts: 57
Rep Power: 17 |
Quote:
I also met this problem, when I run icoFoam on a case with complex 3D shape. courant number becomes bigger and bigger. it seems non reasonable. Do I need to correct it like what you said here? Thank you. Wendy. |
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July 27, 2011, 06:40 |
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#5 |
Member
Tibo
Join Date: Jun 2011
Posts: 68
Rep Power: 15 |
Hi Niklas,
Thanks a lot, that was exactly what I needed. I actually did it with pisoFoam, it works great. Tibo |
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September 24, 2015, 11:07 |
DelT, adjustableTIme,courantNumber
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#6 |
New Member
Isaac Mark Joseph Manasseh
Join Date: Aug 2015
Posts: 3
Rep Power: 11 |
I have set my transient turbulent flow simulation to adjustable time steps. And also set the max. COurant number to 1. I am simulating flow over a smooth cylinder. While using my FFT MATLAB script to plot the dominant frequency as the Strouhal's frequency i realized I got two spikes. One at 2.575 and another peak at 2.795. Reynolds number of : 5.5*10^5. Is this is a physical phenomenon or that my time step delT has been so small to capture the dominant frequency twice. If yes what is the correction that I can do?
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