[swak4Foam] groovyBC for gradual inlet velocity

sixwp · March 31, 2011, 05:17

Hi everyone,

I'm doing a 2D forced convection case with chtMultiRegionSimpleFoam (steady case). I had no problem with relatively slow inlet velocity, but for higher one (100m/s), it diverged at some time!!!

I have tried all I could find in the forum to solve this problem: modified relaxation factors, tolerances, MaxCo number, timesteps, etc... but none was effective (it only delayed the crash).

I bet I can do several cases with gradually higher velocities each (mapping the results of previous case into the next one, and so on). That would be time consuming (not a problem for a 2D case, indeed,but for further studies in 3D...), therefore, I'd like to know:

With this great tool (groovyBC), how would you define the inlet velocity such as varying from 0 m/s to 100 m/s? with a kind of "log"like shape?
My knowledges in this matter are really weak

If this subject has already been discuss in another thread, please, be kind to redirect me to it

Best regards

sixwp · March 31, 2011, 10:09

My bad guys,

I discovered timeVaryingUniformFixedValue and it seems to be perfect

cheng1988sjtu · April 1, 2011, 19:48

How do you implement it? I'm very interested in this It does not render your model to blow up?

sixwp · April 4, 2011, 03:58

Hi Charlie,

Yes it does... I'm still working on it to solve the matter

March 31, 2011, 05:17	groovyBC for gradual inlet velocity	#1
sixwp Member Samuel ARNAUD Join Date: Feb 2011 Location: Grenoble, FRANCE Posts: 39 Rep Power: 15	Hi everyone, I'm doing a 2D forced convection case with chtMultiRegionSimpleFoam (steady case). I had no problem with relatively slow inlet velocity, but for higher one (100m/s), it diverged at some time!!! I have tried all I could find in the forum to solve this problem: modified relaxation factors, tolerances, MaxCo number, timesteps, etc... but none was effective (it only delayed the crash). I bet I can do several cases with gradually higher velocities each (mapping the results of previous case into the next one, and so on). That would be time consuming (not a problem for a 2D case, indeed,but for further studies in 3D...), therefore, I'd like to know: With this great tool (groovyBC), how would you define the inlet velocity such as varying from 0 m/s to 100 m/s? with a kind of "log"like shape? My knowledges in this matter are really weak If this subject has already been discuss in another thread, please, be kind to redirect me to it Best regards __________________ Sam

March 31, 2011, 10:09		#2
sixwp Member Samuel ARNAUD Join Date: Feb 2011 Location: Grenoble, FRANCE Posts: 39 Rep Power: 15	My bad guys, I discovered timeVaryingUniformFixedValue and it seems to be perfect __________________ Sam

April 4, 2011, 03:58		#4
sixwp Member Samuel ARNAUD Join Date: Feb 2011 Location: Grenoble, FRANCE Posts: 39 Rep Power: 15	Hi Charlie, Yes it does... I'm still working on it to solve the matter __________________ Sam

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cheng1988sjtu Member Charlie Join Date: Dec 2010 Location: USA Posts: 85 Rep Power: 16	How do you implement it? I'm very interested in this It does not render your model to blow up?