GEOS-DEV
MGR: Bad linear solver convergence for poromechanics case with fractures
Example 1 (conforming): PoroElastic_conformingFracture_2d_faultSlip switch to MGR:
<LinearSolverParameters
solverType="fgmres"
preconditionerType="mgr"
logLevel="1"
/>
run and observe:
Time: 0.00e+00 s, dt: 100 s, Cycle: 0
Number of element for each fracture state: stick: 80 | slip: 0 | open: 0
Attempt: 0, ConfigurationIter: 0, NewtonIter: 0
( Rflow ) = ( 1.34e+02 ) ( Rsolid ) = ( 4.68e+08 ) ( Rdisplacement, Rtraction, Rtotal ) = ( 1.000000e+00, 1.000000e+00, 1.000000e+00 ) ( R ) = ( 4.68e+08 )
MGR preconditioner: numComponentsPerField = [3, 3, 1]
Linear Solver | Success | Iterations: 80 | Final Rel Res: 8.91421e-07 | Make Restrictor Time: 0 | Compute Auu Time: 0 | SC Filter Time: 0 | Setup Time: 0.238624 s | Solve Time: 2.12301 s
Last LinSolve(iter,res) = ( 80, 8.91e-07 )
flowSolver: Max pressure change: 14074.399 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13586.745 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 1
( Rflow ) = ( 1.48e-06 ) ( Rsolid ) = ( 4.17e+02 ) ( Rdisplacement, Rtraction, Rtotal ) = ( 8.914212e-07, 4.069220e-07, 8.914212e-07 ) ( R ) = ( 4.17e+02 )
MGR preconditioner: numComponentsPerField = [3, 3, 1]
Linear Solver | NotConverged | Iterations: 200 | Final Rel Res: 0.000558784 | Make Restrictor Time: 0 | Compute Auu Time: 0 | SC Filter Time: 0 | Setup Time: 0.234295 s | Solve Time: 5.7737 s
Last LinSolve(iter,res) = ( 200, 5.59e-04 )
flowSolver: Max pressure change: 158.478 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13581.952 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 2
( Rflow ) = ( 5.72e-10 ) ( Rsolid ) = ( 2.33e-01 ) ( Rdisplacement, Rtraction, Rtotal ) = ( 4.981216e-10, 1.023570e-10, 4.981216e-10 ) ( R ) = ( 2.33e-01 )
MGR preconditioner: numComponentsPerField = [3, 3, 1]
Linear Solver | NotConverged | Iterations: 200 | Final Rel Res: 0.0133972 | Make Restrictor Time: 0 | Compute Auu Time: 0 | SC Filter Time: 0 | Setup Time: 0.239527 s | Solve Time: 5.71636 s
Last LinSolve(iter,res) = ( 200, 1.34e-02 )
flowSolver: Max pressure change: 0.047 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13581.951 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 3
( Rflow ) = ( 1.01e-11 ) ( Rsolid ) = ( 3.13e-03 ) ( Rdisplacement, Rtraction, Rtotal ) = ( 6.673488e-12, 1.574757e-12, 6.673488e-12 ) ( R ) = ( 3.13e-03 )
MGR preconditioner: numComponentsPerField = [3, 3, 1]
Linear Solver | NotConverged | Iterations: 200 | Final Rel Res: 0.00803326 | Make Restrictor Time: 0 | Compute Auu Time: 0 | SC Filter Time: 0 | Setup Time: 0.236079 s | Solve Time: 5.72704 s
Last LinSolve(iter,res) = ( 200, 8.03e-03 )
Examples 2 (EDFM): https://github.com/GEOS-DEV/GEOS/blob/develop/inputFiles/poromechanicsFractures/SlipPermeability_embeddedFrac.xml and SlipPermeability_pEDFM_smoke.xml similar convergence issues observed.
The issue can be related to the equation order change after https://github.com/GEOS-DEV/GEOS/pull/2967, see below
new order
old order
hopefully an easy fix
The issue can be related to the equation order
Yes, we need to update the MGR strategies accordingly. I can take a look
The issue can be related to the equation order
Yes, we need to update the MGR strategies accordingly. I can take a look
Thank you, @victorapm!
The issue can be related to the equation order
Yes, we need to update the MGR strategies accordingly. I can take a look
I think we need to change the way these mgr strategies are defined so that we avoid this kind of issue. We fix the ordering statically in the mgr strategies but the actual ordering of the fields is defined at execution. It can get tricky now that we start combining a lot of solvers.
The issue can be related to the equation order
Yes, we need to update the MGR strategies accordingly. I can take a look
I think we need to change the way these mgr strategies are defined so that we avoid this kind of issue. We fix the ordering statically in the mgr strategies but the actual ordering of the fields is defined at execution. It can get tricky now that we start combining a lot of solvers.
To be more precise, the ordering depends on the order in which the functions to add fields to the dofManager are called so technically we can know it before execution but I still think that it is tricky to keep track of this and, if it changes like in this case, we have no test to catch the issue.
https://github.com/GEOS-DEV/GEOS/blob/develop/inputFiles/poromechanicsFractures/PoroElastic_conformingFracture_2d_faultSlip_benchmark.xml still does not converge after the order fix
Time: 0.00e+00 s, dt: 100 s, Cycle: 0
Number of element for each fracture state: stick: 80 | new slip: 0 | slip: 0 | open: 0
Attempt: 0, ConfigurationIter: 0, NewtonIter: 0
( Rflow ) = ( 1.34e+02 ) ( Rsolid ) = ( 4.68e+03 ) ( Rstick Rslip Ropen ) = ( 0.000000e+00 0.000000e+00 0.000000e+00 ) ( R ) = ( 4.68e+03 )
Last LinSolve(iter,res) = ( 200, 2.77e-04 )
flowSolver: Max pressure change = 14105.061 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13609.631 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 1
( Rflow ) = ( 8.18e-06 ) ( Rsolid ) = ( 5.64e-01 ) ( Rstick Rslip Ropen ) = ( 8.128545e-05 0.000000e+00 0.000000e+00 ) ( R ) = ( 5.64e-01 )
Last LinSolve(iter,res) = ( 200, 7.32e-01 )
flowSolver: Max pressure change = 191.322 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13598.476 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 2
( Rflow ) = ( 7.22e-06 ) ( Rsolid ) = ( 4.13e-01 ) ( Rstick Rslip Ropen ) = ( 9.709800e-05 0.000000e+00 0.000000e+00 ) ( R ) = ( 4.13e-01 )
Last LinSolve(iter,res) = ( 200, 7.37e-01 )
flowSolver: Max pressure change = 131.324 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13585.808 Pa
Attempt: 0, ConfigurationIter: 0, NewtonIter: 3
( Rflow ) = ( 3.33e-06 ) ( Rsolid ) = ( 3.04e-01 ) ( Rstick Rslip Ropen ) = ( 9.166976e-05 0.000000e+00 0.000000e+00 ) ( R ) = ( 3.04e-01 )
Last LinSolve(iter,res) = ( 200, 8.87e-01 )
flowSolver: Max pressure change = 62.976 Pa (before scaling)
poroSolver: Global solution scaling factor = 1
flowSolver: Number of negative pressure values: 650, minimum value: -13586.965 Pa
https://github.com/GEOS-DEV/GEOS/blob/develop/inputFiles/poromechanicsFractures/SlipPermeability_embeddedFrac.xml works ok
https://github.com/GEOS-DEV/GEOS/blob/develop/inputFiles/poromechanicsFractures/SlipPermeability_pEDFM_smoke.xml runs and can finish but convergence is not great