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Dear All,<br>
<br>
I got some strange solutions when using SuperLU for a complex
reactive transport simulation. Before the timestep 28, everything
works fine, for both sequential version and parallel version.
Starting from timestep 29, the timestep cannot increase for SuperLU
solver, for both sequential version and parallel version. <br>
<br>
To check this problem, I dumped all the solutions using the
sequential iterative solver (Step 1). Then I rerun this case using
iterative solver (external solver, not from PETSc), SuperLU (from
PETSc) and MUMPS (from PETSc) (Step 2). At every timestep and newton
iteration, the solution is exported, and then the solution is
replaced with the one from the sequential iterative solver from Step
1. In this case, all the matrices and rhs are identical for the
three different solvers. <br>
<br>
To my surprising, solutions from SuperLU at timestep 29 seems not
correct for the first 4 Newton iterations, but the solutions from
iteration solver and MUMPS are correct. <br>
<br>
Please find all the matrices, rhs and solutions at timestep 29 via
the link below. The data is a bit large so that I just share it
through Dropbox. A piece of matlab code to read these data and then
computer the norm has also been attached. <br>
<u><a class="moz-txt-link-freetext" href="https://www.dropbox.com/s/rr8ueysgflmxs7h/results-check.tar.gz?dl=0">https://www.dropbox.com/s/rr8ueysgflmxs7h/results-check.tar.gz?dl=0</a></u><br>
<br>
Below is a summary of the norm from the three solvers at timestep
29, newton iteration 1 to 5.<br>
<br>
Timestep 29<br>
Norm of residual seq 1.661321e-09, superlu 1.657103e+04, mumps
3.731225e-11 <br>
Norm of residual seq 1.753079e-09, superlu 6.675467e+02, mumps
1.509919e-13 <br>
Norm of residual seq 4.914971e-10, superlu 1.236362e-01, mumps
2.139303e-17 <br>
Norm of residual seq 3.532769e-10, superlu 1.304670e-04, mumps
5.387000e-20 <br>
Norm of residual seq 3.885629e-10, superlu 2.754876e-07, mumps
4.108675e-21 <br>
<br>
Would anybody please check if SuperLU can solve these matrices?
Another possibility is that something is wrong in my own code. But
so far, I cannot find any problem in my code since the same code
works fine if I using iterative solver or direct solver MUMPS. But
for other cases I have tested, all these solvers work fine.<br>
<br>
Please let me know if I did not write down the problem clearly.<br>
<br>
Thanks,<br>
<br>
Danyang<br>
<br>
<br>
<br>
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