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Memory usage and internal DOF

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Hi

I'm working on a 3D CFD model with Comsol 5.4 and tring to increese de number of elements but im runing low on RAM (i have 32GB of RAM working with an i7-4790). Im using P1+P1 (first order discretization for pressure and velocity fields) the mesh elements and DOF reported en the messege window are:

  • Complete mesh consists of 697500 domain elements, 91570 boundary elements, and 2682 edge elements.
  • Number of degrees of freedom solved for: 2787596 (plus 5292006 internal DOFs).

And the log reports at the end of the simultion:

  • Solution time: 4356 s. (1 hour, 12 minutes, 36 seconds)
  • Physical memory: 26.61 GB
  • Virtual memory: 28.37 GB

I`m using the default solver configuration. Fully coupled, algebraic multigrid, GMRES solver.

It seems to me that it's using more RAM than it should, and i wonder if it has anything to do with the internal degrees of freedom. I don't really understand what they are, and I can't find anything about internal DOF. I woud like to know if they use same amount of memory as regular DOF. And if is a way to reduce them.

i'll appreciate any information about this, any other thoughts on the subject or if you can tell me if i having a wrong idea about it and my memory usage is normal


0 Replies Last Post 2 mar 2021, 14:23 GMT-5
COMSOL Moderator

Hello Felipe Suarez

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