Dear Jean-Paul, I have the same error with increased max_iterations value:
n_of_refines = 2 pressure_fe_degree = 2 dt = 5e-4 max_iterations = 10000 Iterative method reported convergence failure in step 10000. The residual in the last step was 44.4628. max_iterations = 50000 Iterative method reported convergence failure in step 50000. The residual in the last step was 5.80415e+07. Thank you, Eugeny Pavlyuk среда, 27 февраля 2019 г., 12:06:50 UTC+5 пользователь Jean-Paul Pelteret написал: > > Dear Eugeny, > > Have you tried to increase the “max_iterations” in the parameter file? > Basically, with the way the tutorial program is defined the solver is > currently limited to use the number of iterations defined by the variable > “vel_max_it”. This seems to be prescribed using a parameter file, and is by > default set to 1000 iterations. > > For the way that the problem is solved, I would say that it is expected > that the number of iterations required to achieve convergence in the linear > solver increases as the problem size increases. Does your input problem > have a significantly higher number of degrees of freedom than the original > problem solved in step-35? > > I hope that this helps you. > Best, > Jean-Paul > > On 27 Feb 2019, at 06:49, [email protected] <javascript:> wrote: > > Hello, > i have tried step-35 with other ".inp" files that I have created. It > works fine with original inp but fails with any my inp with the same error > below. > I have tried simple rect without hole by hyper_rectangle and rect with > hole channel_with_cylinder. I use rects with about the same sizes as one in > the original inp. > I have checked I set bounds: input for the left side and zero for the > others. > I tried to change Velocity<dim>::value function to get lower or hier > value. > And I have tried to change pressure_fe_degree, the time step > dt, n_of_refines, and max_iterations in parameter file. > Could you give me any advise? > > error: > An error occurred in line <455> of file > <../dealii/include/deal.II/lac/solver_cg.h> in function > void dealii::SolverCG<VectorType>::solve(const MatrixType&, > VectorType&, const VectorType&, const PreconditionerType&) [with MatrixType > = dealii::SparseMatrix<double>; PreconditionerType = > dealii::SparseILU<double>; VectorType = dealii::Vector<double>] > The violated condition was: > false > Additional information: > Iterative method reported convergence failure in step 1000. The residual > in the last step was 800.487. > > I have attached here one of my inp. > > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > For more options, visit https://groups.google.com/d/optout. > <nsbench2-simple.inp> > > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
