Parallel evaluation of expressions in Global Evaluation

Breno Topology optimization and Finite Element specialist

Please login with a confirmed email address before reporting spam

Is it possible for Expressions in a Results->Derived Values->Global Evaluation node to all be computed in parallel?

I'm running view factor calculations, which require surface integrations and the evaluation of the rad.radopu function. The stationary solver (for a Surface-To-Surface Radiation problem) takes only 2 and a half minutes, while the view factor calculations take up to two hours... It seems that the evaluations are performed using only one core of my CPU.

For reference, my setup is similar to this COMSOL tutorial: https://www.comsol.com/model/view-factor-computation-20701. except that I define the surface areas and the view factors in a Variables node.


1 Reply Last Post 21 ago 2025, 19:58 CEST
Edgar J. Kaiser Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 20 hours ago 21 ago 2025, 19:58 CEST

Hi Breno,

I am frequently having similar issues with complex post processing. Defining variables doesn't help because they get evaluated again when called in post processing. One workaround can be to define global state variables and assign the variables to them. State variables are stored in the solution and are available without reevaluation. States do not carry a unit and you must take care of the units by yourself.

Expensive expressions are obviously calculated much faster within the solver code than in post processing code.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hi Breno, I am frequently having similar issues with complex post processing. Defining variables doesn't help because they get evaluated again when called in post processing. One workaround can be to define global state variables and assign the variables to them. State variables are stored in the solution and are available without reevaluation. States do not carry a unit and you must take care of the units by yourself. Expensive expressions are obviously calculated much faster within the solver code than in post processing code. Cheers Edgar

Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

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.