I added Lithium Ion battery to a 3D physics to get 3D electrochemical properties. When I run the time dependent solver, I face this error: Returned solution is not converged. How can I solve this error.
First of all, check all the boundary conditions you have applied. If everything seems fine, then try to coarse the meshing. Many times solutions are not converged in case of very fine meshing.
Hello Mohammad,
Equally a mesh that is too coarse will often fail.
Please see the following discussion.
https://www.researchgate.net/post/Why_doesnt_iterative_solver_converge_in_COMSOL
Furthermore, the following links may be useful:
https://www.comsol.com/blogs/improving-convergence-multiphysics-problems/
http://evgeni.org/oldfish/Top_nine_hints_for_working_with_Comsol#Hint_2._Get_it_to_converge_and_get_an_accurate_solution
https://community.cmc.ca/docs/DOC-1453
Hope it helps,
Jules
Tips
1 check the geometry first via form union option.
2 Material properties assignment is must be and sometime you add constant value.
3 Initial values should be added for transient solution or sometime call from stationary solution.
4 Meshing properly
5 Multi-physics problem activate the coupling parameter and its link up between two physics module.
If you want to go in depth than the tips given above, here are some more options:
- Use structural meshes where you think you are getting the error (or use everywhere), Play with adaptive mesh refinement in solver or adapt option inside mesh node ~ Use this everytime to fine your meshes
- Use the Generalized Alpha rather than BDF with strict or intermediate time stepping ~ this improves the convergence in many cases for me
- Play with the tolerances (relative and absolute both) ~ sometimes if I change from factor to manual absolute tolerance (with enough time-discretization) it works.
- Get the Jacobian update on every iteration than minimum ~ very important for non-linear solvers
- Increase the number of maximum iterations ~ good option if you are using very fine tolerances
- Change from fully coupled to segregated solvers ~ if you have many integrated physics
- Use assembly in geometry and play with source to destination mesh refinements ~ when you are defining BCs or ICs inside the domains
- Change scaled values of variables to manual and use values of their respective maximums ~ very helpful at the start of simulation fails
Will update more later.
- Badges
- Science topic
- Similar topics
- Biological Science
- Kinesiology
- Running