Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Convergence of non-isothermal flow simulation stationary

Please login with a confirmed email address before reporting spam

Hello,

i have problems with my simulation of non-isothermal flow (including surface-to-surface radiation, but i think the problem is the fluid flow). The fluid flow is considered to be laminar. The simulation gives me the required results if i use a time-dependend study and just consider it stationary if the results dont change anymore, but this requires too much computational time.
Why is it not possible (or easy) to use a stationary study here?
Is it a problem with the mesh or the solver?
I tried it with very coarse mesh and very fine mesh, but since its 3D i cannot go much finer without running out of memory...

Any hints are appreciated, thanks in advance!

Edit:
I made a simplified 2D version of the simulation and compared the mesh density. It converges sometimes, but it takes a lot of iterations. And even a normal mesh in 2D is too much in 3D...
Of course i could increase the number of maximum iterations, but it takes too long...
And what does the error message at the coarser mesh mean? (see attached file)


0 Replies Last Post Mar 1, 2016, 4:01 a.m. EST
COMSOL Moderator

Hello E Sing

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.