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-   -   Matrix solver in OpenFoam (https://www.cfd-online.com/Forums/openfoam/98541-matrix-solver-openfoam.html)

ahmed_khatibs March 13, 2012 10:19

Matrix solver in OpenFoam
 
hi to all,
I want to know for my project, Which matrix solver is most commonly used in OpenFoam form this
  • PCG
  • PBiCG
  • GAMG
  • smoothSolver
  • diagonal solver

Linse March 13, 2012 12:25

Hi Ahmed,

I don't know too much about the usage of the different solvers. But to my knowledge the PBiCG points back to the PCG at some point within OpenFOAM...

calim_cfd March 13, 2012 12:58

linear solvers comprise
Code:

• BICCG/ - Diagonal incomplete LU preconditioned BiCG solver1
• diagonalSolver/ - diagonal solver for both symmetric and asymmetric problems
• GAMG/ - Geometric agglomerated algebraic multigrid solver (also named Generalised geometric-
algebraic multi-grid
in the manual)
• ICC/ - Incomplete Cholesky preconditioned Conjugate Gradients solver2
• PBiCG/ - Preconditioned bi-conjugate gradient solver for asymmetric lduMatrices using a run-
time selectable preconditioner
• PCG/ - Preconditioned conjugate gradient solver for symmetric lduMatrices using a run-time
selectable preconditiioner
• smoothSolver/ - Iterative solver using smoother for symmetric and asymmetric matrices
which uses a run-time selected smoother

now you need to know whether your variable yields a symmetric or asymmetric matrix to choose the right solver..


note that the differences might not be so significant depending on the case and mesh....but for pressure, it's kinda common try the GAMG solver since it seems to be faster.. but as to accuracy i can't tell you which one to pick

luckycfd October 3, 2013 15:12

Hi ahmed,
please explain more about your question?

regards,
Hassan


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