[aspect-devel] Benchmark

[I. van Zelst]

Dear Timo,

That was indeed a bug in the code, but it does not explain the weird
convergence behaviour. If anything, the results got worse, as can be seen
in the updated figures that are attached. I also enclose the new .cc file.
Do you have any other ideas for this behaviour?

Kind regards,
Iris


2014-06-30 19:36 GMT+02:00 Timo Heister <timo.heister at gmail.com>:

> Iris,
>
> not sure this explains the result but:
> > *p=x*y*z+x*x*x*y*y*y*z-5/32;
> Here 5/32 gives 0, because it is an integer division. Write it as "5./32.".
>
>
> On Mon, Jun 30, 2014 at 7:06 AM, I. van Zelst <i.vanzelst at students.uu.nl>
> wrote:
> > Dear all,
> >
> > I have been trying to make a new benchmark for Aspect, based on the paper
> > 'Large-scale adaptive mantle convection simulation' from Carsten
> Burstedde
> > in 2013. Subsequently, the benchmark has been dubbed the 'Burstedde'
> > benchmark.
> > However, a problem I encounter is that the pressure error between the
> > analytical solution and the numerical solution does not converge with
> > resolution, as can be seen in the attached figure 'errors.pdf’.
> > Furthermore, the minimum and maximum pressure in the system, for which an
> > analytical value is available diverges more and more from the analytical
> > solution as the resolution is increased, as can be seen in the attached
> > figure 'pressure.pdf'.
> > Could it be that the elements in the corners of the domain are
> constrained
> > by too many (?) boundary conditions: these elements have three faces for
> > which velocities are prescribed in the x, y and z directions.
> > In this case, could it be that these corner elements lead to a matrix
> which
> > the solver cannot handle well, resulting in excessive pressures at the
> > corners and non-converging velocities ?
> >
> > Would anybody like to have a look at the benchmark to see whether this is
> > indeed what goes wrong? I have included the .cc file and the input file,
> > which could be put in the folder burstedde, which would be a folder of
> > benchmark.
> >
> > Kind regards,
> > Iris van Zelst
> >
> > _______________________________________________
> > Aspect-devel mailing list
> > Aspect-devel at geodynamics.org
> > http://lists.geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel
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