Convergence graphs pressure value is deviating


#1

i tried many and i cant converge the results can u help e out to find where i m going wrong
https://www.simscale.com/workbench/?pid=3967403048539346781#tab_1-0
2Newrun ----> Run1
(delete this message before posting)


#2

Hi @sjay!

I will have a look at your project later on as I am in a lecture at the moment (maybe one of the @PowerUsers_CFD can jump in before I do later) but let me give you some tips that might improve convergence:

  • Check all the boundary conditions

  • Adapt the relaxation factor

  • You can first turn turbulence off and check if residuals become steady for pressure/velocity and then turn turbulence on working again with the relaxation factor

  • Change the tolerances to 1e-7 or 1e-8

Let me know if some of the tips helped - maybe the PowerUser have some more tips.


Cheers!

Jousef


#3

Hi @sjay, in addition to what @jousefm has mentioned, you could monitor average values or forces to determine if you need tighter pressure convergence. Sometimes the accuracy improvement is so minor your fighting just to get a good looking convergence plot instead of accurate results.

Kind regards,
Darren


#4

true that but I want a convergence I m doing my final year project. so compared with fluent users they can control their results I just wanted to know whether simscale got any option to do it


#5

Hi @sjay!

If that was a question then I can answer it with “yes”. Under Numerics you have different possibilities to adapt the settings and control the convergence so to speak.

Let us know if you need any further help!

Best,

Jousef


#6

how can I control the pressure convergence can u look upon my project and tell me where I went wrong?
can u help me out with the setting for a nicely converged graph?
and also when I use conquer in post-processing it doesn’t show…


#7

I hope this is good enough for you. Still the y-plus value is too high. I recommend remeshing it with the boundary layers. For that you need to explode your geometry into faces and then assign them for layer inflation.

https://www.simscale.com/projects/rajan19us/hope_to_be_final_runs/

Regards,
Rajan


#8

i tried to do that once and when i get to use it some how flow went in so i sticked to this