[CIG-SHORT] Problem with modeling viscoelastic magma chamber

[Brad Aagaard]

On 06/20/2014 12:41 PM, Francisco Delgado wrote:
> Hello, I've been adapting the magma chamber example to include a
> viscoelastic medium surrounding the pressurized cavity and when I run the
> code I get the following error:
>
>
>   >>
> /Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/problems/TimeDependent.py:137:run
>
>   -- timedependent(info)
>
>   -- Preparing for prestep with elastic behavior.
>
> Fatal error. Calling MPI_Abort() to abort PyLith application.
>
> Traceback (most recent call last):
>
>    File
> "/Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/apps/PetscApplication.py",
> line 64, in onComputeNodes
>
>      self.main(*args, **kwds)
>
>    File
> "/Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/apps/PyLithApp.py",
> line 135, in main
>
>      self.problem.run(self)
>
>    File
> "/Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/problems/TimeDependent.py",
> line 141, in run
>
>      dt = self.formulation.getTimeStep()
>
>    File
> "/Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/problems/Formulation.py",
> line 218, in getTimeStep
>
>      dt = self.timeStep.timeStep(self.mesh(), self.integrators)
>
>    File
> "/Applications/pylith-2.0.0-darwin-10.6.8/lib/python2.7/site-packages/pylith/problems/TimeStepUniform.py",
> line 87, in timeStep
>
>      "step of %12.4e." % (self.dtN, dtStable))
>
> RuntimeError: Current nondimensionalized time step of   1.0000e+00 exceeds
> the nondimensionalized stable time step of   5.6334e-03.
>
> application called MPI_Abort(MPI_COMM_WORLD, -1) - process 0
>
> /Applications/pylith-2.0.0-darwin-10.6.8/bin/nemesis: mpirun: exit 255
>
> /Applications/pylith-2.0.0-darwin-10.6.8//bin/pylith:
> /Applications/pylith-2.0.0-darwin-10.6.8/bin/nemesis: exit 1
>
>
> What does this error mean and how can I fix it??

The part of the error message you want to focus on is shown at the 
bottom: "RuntimeError: Current nondimensionalized time step of 
1.0000e+00 exceeds the nondimensionalized stable time step of   5.6334e-03."

See section 4.1.3.1 Nondimensionalization, section 4.2.4 Time Stepping, 
and section 5.1.4 Stable time step of the PyLith manual.

Regards,
Brad