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-   -   Help: BSCW simulation residuals not converging (https://www.cfd-online.com/Forums/su2/217296-help-bscw-simulation-residuals-not-converging.html)

itsthekv May 7, 2019 10:17

Help: BSCW simulation residuals not converging
 
1 Attachment(s)
Dear All,

I am a fairly new user, trying to graduate from tutorials to finally running some bespoke cases. As a first step, I have taken the BSCW wing (fine tet mesh) from Aeroelasticity Prediction Workshop 2 (AePW2) website ( https://nescacademy.nasa.gov/worksho...W/analystsInfo ) and am trying to simulate inviscid transonic flow over the wing. For the configs, I have adapted the file provided in inviscid OneraM6 tutorial case.

So far, I have changed the configs (markers, names etc) to match with the mesh and got the simulation to run. However, the simulation is not converging even with very low values of CFL (tried even 0.01). The residuals oscillate between -1 and -3 and refuse to reduce further. :confused:

Can someone point out the mistake that I am doing? :o I am attaching the config file that I used.

Thanks for the help

wallym May 10, 2019 05:24

Hi Vishnu,

Thank you for reaching out! and I am happy you using SU2.
Your config file looks good. I cant access the mesh file you referred to, however, my first thought would be your boundary conditions...particularly the far-field. I generally see this issue when the flow is unsteady, or the due to the far-field.

I hope this helps, but lets us know!

-Wally

itsthekv May 10, 2019 13:10

Hi Wally,
Thanks for the reply.
I have tried to imitate the OneraM6 tutorial with only the mesh changed to the BSCW mesh given. I also changed the markers, reference geometric dimensions etc. to match with the mesh.
Apart from that, I have kept the boundary conditions, including farfield, as same as that in the tutorial.
However, I have made some progress by further tuning some parameters, like -
CFL_NUMBER= 0.5
LINEAR_SOLVER_ITER= 2

Now, there is a downward trend in the residuals after a peak (in 2 hrs on running on 240 cores). I will run longer and post the results in this space.

Thanks again, for the help.
- Vishnu

wallym May 11, 2019 13:37

Good luck! Let us know if you need any help!


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