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Bi-Conjugate Gradient Stabilized solver did not converge |
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September 3, 2020, 05:41 |
Bi-Conjugate Gradient Stabilized solver did not converge
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#1 |
New Member
swaroop
Join Date: Sep 2020
Posts: 3
Rep Power: 5 |
Hi CFD Lovers,
I am new to CFD world hence many of the technical i dont know. Can you please help me out with this issue. I am doing internship trying to generate airfoils for BLI using PARSEC method. So my guide has simulated an architecture and now it seems that when I run his simulation it is saying "WARNING: insufficient precision on multigrid level 15, nRows = 2 AMG coarsening halted. Bi-Conjugate Gradient Stabilized solver did not converge ! A floating point exception has occurred: floating point exception [Invalid operation]. The specific cause cannot be identified. Please refer to the troubleshooting section of the User's Guide. Context: star.coupledflow.CoupledImplicitSolver Command: Automation.Run error: Server Error". Please see attached the images of the mesh to better understand the project. Could you please me out with this!! |
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September 4, 2020, 05:31 |
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#2 |
Senior Member
Ping
Join Date: Mar 2009
Posts: 556
Rep Power: 20 |
so you are saying that you have changed nothing and his previously working model will now no longer run - that would be very surprising unless maybe the version of star is different?
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September 14, 2020, 07:00 |
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#3 | |
Senior Member
Kushal Puri
Join Date: Nov 2013
Posts: 182
Rep Power: 12 |
Quote:
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September 26, 2020, 18:30 |
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#4 |
New Member
swaroop
Join Date: Sep 2020
Posts: 3
Rep Power: 5 |
Thanks for the reply. I tried to reinitialize thats when everything went wrong. So without reinitializing the original file, I tried to run then it started to converge. I don't know what's the logic behind. . I dont know to tweak in StarCCM+ like to play with AMG solver and CFL number and to use other accelerators. Could you share your views and suggestions
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September 26, 2020, 23:31 |
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#5 |
Senior Member
Ping
Join Date: Mar 2009
Posts: 556
Rep Power: 20 |
it is very common to have to manually 'baby' along a cfd case when more advanced physics or complex flow features exist and what your experience probably indicates is that the previous converged run was started with more basic settings to get it going before changing mid-stream to the desired settings or even boundary conditions.
btw, if you know the steps taken to achieve this you can now automate it using a simulation operation. |
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