Hi Dmitry, the error is from the constraint solver that solves for the phase composition given some state variables (e.g. pressure, temperature). This is called in the volume variables. Most likely there is something wrong in your analytic Jacobian which leads to a non-physical solution and then the phase composition cannot be determined.
The constraint solver solves a small local linear equation system, this is I guess why the error message say “Matrix”. But the error message is a bit unfortunate since we don’t solve matrices but linear equation systems. I’ll have a look and maybe propose a better message. Timo -- _________________________________________________ Timo Koch phone: +49 711 685 64676 IWS, Universität Stuttgart fax: +49 711 685 60430 Pfaffenwaldring 61 email: [email protected] D-70569 Stuttgart url: www.iws.uni-stuttgart.de/en/lh2/ _________________________________________________ > On 26. May 2020, at 22:47, Dmitry Pavlov <[email protected]> wrote: > > Hello, > > I am a bit puzzled about this error: > > [solve:/home/dpavlov/DUMUX/dumux/dumux/material/constraintsolvers/misciblemultiphasecomposition.hh:182]: > Matrix for composition of phases could not be solved. > > I have two phase (wetting + nonwetting), three component (water + oil + > soluble) problem. I am using the box method. The error arises even if the > concentration of the soluble is zero in both initial and boundary conditions. > It arises with non-zero concentration as well. I am not sure I understand > what it means. It happens with analytic Jacobian but not with numeric, though > the two Jacobians are close and the resulting deltaU are close. There is > constant influx boundary condition and Dirichlet condition implemented as > neumann() on the other boundary. > > Here is the output with some debug printing of most simple (2x1 grid) case. > > Analytic Jacobian, first step: > > deltaU = [ > -8.186022503050234e+05 1.513202330364747e-11 0.000000000000000e+00 > -3.593011248700532e+05 1.739221259891074e-23 0.000000000000000e+00 > 1.000000000000004e+05 1.100997636307169e-33 0.000000000000000e+00 > -8.186022503050242e+05 1.513202330364747e-11 0.000000000000000e+00 > -3.593011248700537e+05 1.739221259882897e-23 0.000000000000000e+00 > 1.000000000000004e+05 6.193670380440475e-34 0.000000000000000e+00] > > Update: x^(k+1) = x^k - deltax^k[Krank 0 caught an exception while > assembling:NumericalProblem > [solve:/home/dpavlov/DUMUX/dumux/dumux/material/constraintsolvers/misciblemultiphasecomposition.hh:182]: > Matrix for composition of phases could not be solved. > Throwing NumericalProblem for trying with smaller timestep. > Newton: Caught exception: "NumericalProblem > [assemble_:/home/dpavlov/DUMUX/dumux/dumux/assembly/fvassembler.hh:421]: A > process did not succeed in linearizing the system" > Newton solver did not converge with dt = 0.001 seconds. Retrying with time > step of 0.0005 seconds > > Numeric Jacobian, first step > > deltaU = [ > -8.186005351489465e+05 1.513202513724707e-11 0.000000000000000e+00 > -3.593004585059684e+05 1.557296475841733e-23 0.000000000000000e+00 > 1.000026453219807e+05 3.232270669529124e-24 0.000000000000000e+00 > -8.186005600992423e+05 1.513202513724701e-11 0.000000000000000e+00 > -3.593004843413417e+05 1.532724499151271e-23 0.000000000000000e+00 > 1.000034579193550e+05 3.723737820455500e-24 0.000000000000000e+00] > result = 1 > > Update: x^(k+1) = x^k - deltax^k[K > Newton iteration 1 done, residual = 3.317e-06 > > > Best regards, > > Dmitry > > > _______________________________________________ > Dumux mailing list > [email protected] > https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
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