Convergence issue

Project Support
1

Hi there,

I am modelling wind flow around a structure and have got results which i am happy with for a wind angle of 90 degrees to the building face. When i rotate the model by 45 degrees and use the same settings the convergence criteria are not being met and look different to the 90 degree wind angle.

Does anyone know a reason why this may be occurring, any advice would be appreciated.

The 90 degree model is here

The 45 degree model is here

I understand that the run time is not as long, but i noticed the convergence not being similar,

EDIT:
I have also realised that my solution for the force did not reach a steady value, meaning the model has not converged
Thanks

2

Hi!

You definitely need more iterations in the 45° AoA simulations, as the residuals are very high. I would suggest to go for at least 3000.

The 0° AoA also needs more iterations as you state, until the force plots are converged, or oscillate in a stable pattern.

Another option you can try to improve the convergence is to use the Hex-Dominant mesh algorithm.

3

Hi there, I will let the simulation run for a longer period overnight and see what comes out. Thank you

1 Like