[wkholy]

I tried to simulate Nasa stage 35 using su2 7.3.1.
It can run in first 10 steps when the rotational speed is set much smaller. However, it will get NaN for residual computation when the rotational speed gets larger.

Error in "void CSolver::SetResidual_RMS(const CGeometry*, const CConfig*)":
-------------------------------------------------------------------------
SU2 has diverged (NaN detected).
------------------------------ Error Exit -------------------------------

Please see the attachment for the settings.

Hope it can be resolved.

[koray]

Hi Kyle. I think your setup is ok. Is it possible for you to solve both rotor and stator separately first and then solve it together starting from the converged data. Convergence of compressor flows are very sensitive to initial data thanks to complex 3D flow field and adverse pressure gradients. With the same logic, you may want to keep CFL low along the computation. And I suppose your mesh is ok. Good luck.

[wkholy]

Originally Posted by koray

Hi Kyle. I think your setup is ok. Is it possible for you to solve both rotor and stator separately first and then solve it together starting from the converged data. Convergence of compressor flows are very sensitive to initial data thanks to complex 3D flow field and adverse pressure gradients. With the same logic, you may want to keep CFL low along the computation. And I suppose your mesh is ok. Good luck.

Thanks, Koray. I have successfully run the case. Just the efficiency cannot converge but increase to 1000 and more. I have tried the tutorial case. Yet the efficiency is not stable as I change the time step from 3000 to 5000. SU2 CFD version is 7.3.1.

[ashvin]

Originally Posted by wkholy

Thanks, Koray. I have successfully run the case. Just the efficiency cannot converge but increase to 1000 and more. I have tried the tutorial case. Yet the efficiency is not stable as I change the time step from 3000 to 5000. SU2 CFD version is 7.3.1.

Hello Kyle,
I stumbled upon this thread looking for why my efficiency values are all zero in my history.csv for my rotor37 case. I am using V740 and I am trying to figure out how to get efficiency data in history.csv file. Is there an option I need to add in SU2 card?
Thanks
Ashvin

[wkholy]

Originally Posted by ashvin

Hello Kyle,
I stumbled upon this thread looking for why my efficiency values are all zero in my history.csv for my rotor37 case. I am using V740 and I am trying to figure out how to get efficiency data in history.csv file. Is there an option I need to add in SU2 card?
Thanks
Ashvin

Hi, Ashvin. I think the 7 version of SU2 cannot directly output turbo parameters in history.csv. But you can conveniently revise output_physics.cpp for a new output file of turbo efficiency or collect screen output and extract the turbo data using python. If the optimization is your goal, then SU2 version 7 can only deal with single zone problem of turbomachinery from my understanding.

[ashvin]

Hello Kyle,
Thanks! I will work on that! I am only using SU2 to perform the CFD solutions.
Thanks
Ashvin