[CIG-LONG] Crash Error in TimeIntegrand

[María Helga Guðmundsdóttir]

Hi Walter,

This seems to have resolved the TimeIntegrand error issue – thanks!

However, I have another question that relates to one of the modifications you and George made to the model. The way the model ends are set up now, there is effectively no inflow of material, because the two ends of the model move at a rate equal to the velocity of the inflowing material. As a result, the models end up shortening more and more the longer they run, and with some of the smaller/shorter models, we practically run out of material in the late stages of the run. (Obviously you can't try to simulate 70 km of displacement on a 60 km model if the model is going to shorten by the full amount of the displacement.)

George and I experimented a bit with the Front/BackEquations, but we were unable to modify them to allow the model to actually retain its dimensions or change them more slowly; we always got the "wall is moving in the wrong direction" error. Is there any workaround that will allow us to keep the models at a constant size, but have material flow in and out of the two ends? Or should we try something else, like just defining the models to be 70+ km longer than we need them to be at the start, and allow that material to be gradually lost as the simulation progresses?

Thanks,
Maria



On May 9, 2012, at 9:29 AM, María Helga Guðmundsdóttir wrote:

> Great, thanks for catching that. I'll take those lines out and run a test model to see what happens.
> 
> -M
> 
> María Helga Guðmundsdóttir
> MS Student, Stanford University
> Geological and Environmental Sciences
> mariahg at stanford.edu
> 
> On May 8, 2012, at 6:10 PM, Walter Landry wrote:
> 
>> Walter Landry <walter at geodynamics.org> wrote:
>>> María Helga Guðmundsdóttir <mariahg at stanford.edu> wrote:
>>>> Hi Walter,
>>>> 
>>>> I've been running the restraining bend models that George Hilley has
>>>> been troubleshooting with you lately, with mixed results. Two of
>>>> them have run fine upto the amount of displacement we want, but
>>>> another four models have crashed in an identical fashion at
>>>> completely different points during the run (timesteps 8, 11, 90, and
>>>> 289 respectively, with total displacements of 4, 10, 17, and
>>>> 37km).
>>> 
>>> The problem is the mesh distortion.  I am attaching a picture taken
>>> from the inside, and you can see that the height of the mesh almost
>>> goes to zero.  I am not sure what to do about this. What do you change
>>> between the runs that work and the runs that do not?
>> 
>> One thing I noticed about your input file is that in EulerDeform, you
>> have the lines
>> 
>>  "staticTopFront": "True",
>>  "staticTopBack": "True",
>> 
>> Those should be False or just not there.  That will induce grid
>> distortion at outflow, because while the bulk is thinning, the
>> boundary is kept high.
>> 
>> Cheers,
>> Walter Landry
> 
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