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-   -   Is there a way to enforce my timestep? (https://www.cfd-online.com/Forums/openfoam-solving/94223-there-way-enforce-my-timestep.html)

Shawn_A November 9, 2011 13:30

Is there a way to enforce my timestep?
 
I'm using pimpleDyMFoam to simulate a vertical axis wind turbine with a stationary outer domain and a rotating inner domain using the ggi. I would like to be able to strictly enforce my timestep. I have tried to raise my maxCo to 100 (yes, I know the implications) but the deltaT used in the solution will never go higher than 0.000556 (my desired deltaT is 0.00278 which corresponds to 1 deg rotation at 60 RPM). The maxCo in the solution is ~7.33 so it never approaches 100.

Is there another parameter I should look at to get my deltaT to where I want? Convergence doesn's seem to be an issue at this Co/deltaT (7.3/5.6e-4) yet.

Thanks,
Shawn

kwardle November 9, 2011 13:40

Is there a reason you cannot simply change system/controlDict such that:

deltaT 0.00278;
adjustTimeStep no;

This should give you a constant time step.
-Kent

Shawn_A November 10, 2011 11:53

Wow...I guess I've been looking at this too long. That command is literally 2 lines above maxCo.

Thanks Kent!


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