Time Solver

[Joshua Gorham]

Hi all, I am trying to solve the time dependant coupled equations displayed below:

 

(The time derivative is passed via the LT Submatrix)

 

I am currently getting issues with time solvers and when running the code, it produces this error:

I have modified the operator to admit a lambda function:

OpDomainPVMixScalarTimesDiv is an alias for OpMixScalarTimesGrad:

This operator has been changed in the core level, and now looks like this:

The time manager function that I have used is:

The Command line that I use is:

 

mpirun -np 1 ./hydromechanics_time_dependant -file_name simple_square.cub ksp -ksp_monitor -density 0.0509684 -order_pressure 1 -prescribed_pressure_1 -10 -prescribed_pressure_2 -10 -conductivity 10 -water_table -100 -unit_weight 0 -ts_monitor -ts_dt 1 -ts_max_time 1 -ts_type beuler -ksp_type gmres -pc_type lu -pc_factor_mat_solver_type mumps -snes_monitor -snes_monitor -snes_max_it 1

 

 All the best,

Josh

[Karol Lewandowski]

I do not really see the error here, it seems like it is diverging. Can you try running with "-ts_adapt_type none"

Also, have you verified your jacobian matrix? 

I suggest maybe running an extremely small problem with a minimum number of elements and "-snes_fd" parameter. It will use the finite difference method for Jacobian.

[Lukasz Kaczmraczyk]

Josh, 

That should converge in one step. I would strat with switching off line searcher, add this to param_file.petsc, or command line,

-snes_linesearch_type basic

Your error is related to inconstancy between the right hand side, and the left hand side, so Karol suggestion is good.  Try 

-snes_fd 

and check if you get expected results. If that is the case, you should look at opertaors pushed to calculate matrix, i..e the left hand side.

L.