[CIG-LONG] Help! SNAC Benchmark: Parallel-Plate Viscometer
Jean Liu
jeanpaulyn.liu at utoronto.ca
Thu Aug 12 11:04:44 PDT 2010
Hi Eunseo,
Is it possible for you to run my input file for the benchmark and send
me the output files you get? I want to check to see if it's a problem
with my installation of SNAC.. I attached my input file to this email.
Thank you for all of your help and patience! =)
- Jean
Quoting Eunseo Choi <echoi at ldeo.columbia.edu>:
> Hi, Jean
>
> The "tetra shear stress" is the second invariant of stress and "max.
> shear stress" is 0.5*(Sig1-Sig3), where Sig1 and 3 are the largest and
> the least principal stresses.
> For comparison with the figure in the manual, please plot "tetra shear
> stress".
>
> "shear/normal stress @ 30d" are used only in special cases.
> Sorry for the confusing naming. I'll try to improve them in the future.
>
> Eunseo
>
> Jean Liu wrote:
>> Hi Eunseo,
>>
>> In the no-slip case, my velocities are still greatest on the wall
>> boundary condition (instead of where it's supposed to be pushing
>> out in the x-direction), and I get the shear and normal stress from
>> the SNAC output, visualized on Paraview.
>>
>> How do you get stress invariant as an output? When I load the .vts
>> and .pvts files into Paraview, I get the option of plotting:
>>
>> - plastic strain
>> - strain rate
>> - pressure
>> - hydrostatic pressure
>> - tetra shear stress
>> - max. shear stress
>> - von mises stress
>> - shear stress @30d
>> - normal stress @30d
>> - failure potential @30d
>> - phase
>> - viscosity
>> - velocity
>> - force
>> - temperature
>>
>>
>>
>>
>>
>> Quoting Eunseo Choi <echoi at ldeo.columbia.edu>:
>>
>>> I see. Then, the stress value you compute must be different from what's
>>> plotted in the manual.
>>>
>>> First of all, velocity field looks better in the no-slip case?
>>> And, what does the plot of stress invariant look like?
>>> How did you get the shear and normal components of stress?
>>>
>>>
>>> Eunseo
>>>
>>>
>>>
>>> On 08/11/2010 05:04 PM, Jean Liu wrote:
>>>> Hi Eunseo!
>>>>
>>>> I tried that before, as well, and I ended up getting an
>>>> asymmetric pattern for stress.. (I attached the screenshot to
>>>> this email)
>>>>
>>>> - Jean
>>>>
>>>>
>>>>
>>>>
>>>> Quoting Eunseo Choi <echoi at ldeo.columbia.edu>:
>>>>
>>>>> Hi, Jean
>>>>>
>>>>> No-slip conditions should be added on the moving walls.
>>>>> So, insert the following block of XML code into each of the top and
>>>>> bottom BC sections:
>>>>> ==================
>>>>> <struct>
>>>>> <param name="name"> vx </param>
>>>>> <param name="type"> double </param>
>>>>> <param name="value"> 0.0 </param>
>>>>> </struct>
>>>>> <struct>
>>>>> <param name="name"> vz </param>
>>>>> <param name="type"> double </param>
>>>>> <param name="value"> 0.0 </param>
>>>>> </struct>
>>>>> ==================
>>>>>
>>>>> And please update me on the results!
>>>>> Thanks.
>>>>>
>>>>> Eunseo
>>>>>
>>>>> ps. Do you mind posting this reply on the cig-long list?
>>>>>
>>>>>
>>>>> Jean Liu wrote:
>>>>>> Hi Eunseo!
>>>>>>
>>>>>> I thought it was straightforward, too, but when I ran it, my
>>>>>> velocity vectors looked a bit different from yours: my
>>>>>> velocities were greater at the wall velocity boundary
>>>>>> condition, then at the part where the material is being
>>>>>> squeezed out. Plus, to compare to the second invariant of
>>>>>> stress, I just added the shear and normal components on
>>>>>> paraview and got different numerical values (but similar
>>>>>> patterns).
>>>>>>
>>>>>> Could you take a look at my input file? I'm not sure if it's a
>>>>>> problem with my installation of SNAC (when I ran make check,
>>>>>> there were quite a few Fails), or if everything is okay..
>>>>>>
>>>>>> I also attached a screenshot of my Paraview results.
>>>>>>
>>>>>> Thanks for all of you help again, Eunseo!! I'm sorry for being
>>>>>> such a nuisance..
>>>>>>
>>>>>> - Jean
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Quoting Eunseo Choi <echoi at ldeo.columbia.edu>:
>>>>>>
>>>>>>> Dear Jean
>>>>>>>
>>>>>>> I produced the benchmark results but don't have the original
>>>>>>> input file.
>>>>>>> As far as I remember, it should be straightforward to construct an
>>>>>>> input file for that problem.
>>>>>>> What are the problems you ran into?
>>>>>>>
>>>>>>> Eunseo
>>>>>>>
>>>>>>> Jean Liu wrote:
>>>>>>>> Hi!
>>>>>>>>
>>>>>>>> I was wondering if anyone has the input file for the SNAC
>>>>>>>> benchmark parallel-plate viscometer problem that was used
>>>>>>>> for the figures in the SNAC manual?
>>>>>>>> I'm trying to get a comparison for my output, but I'm running
>>>>>>>> into a few problems...
>>>>>>>>
>>>>>>>> Thanks!
>>>>>>>>
>>>>>>>> - Jean
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> CIG-LONG mailing list
>>>>>>>> CIG-LONG at geodynamics.org
>>>>>>>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-long
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> =====================================
>>>>>>> Eunseo Choi
>>>>>>> Post-Doctoral Research Scientist
>>>>>>>
>>>>>>> Lamont-Doherty Earth Observatory
>>>>>>> 305c Oceanography
>>>>>>> P.O. Box 1000
>>>>>>> 61 Rt. 9W
>>>>>>> Palisades, NY 10964-8000
>>>>>>>
>>>>>>> http://www.ldeo.columbia.edu/~echoi
>>>>>>> Phone: 845-365-8813 Fax: 845-365-8156
>>>>>>> =====================================
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>>
>>>>>
>>>>> --
>>>>> =====================================
>>>>> Eunseo Choi
>>>>> Post-Doctoral Research Scientist
>>>>>
>>>>> Lamont-Doherty Earth Observatory
>>>>> 305c Oceanography
>>>>> P.O. Box 1000
>>>>> 61 Rt. 9W
>>>>> Palisades, NY 10964-8000
>>>>>
>>>>> http://www.ldeo.columbia.edu/~echoi
>>>>> Phone: 845-365-8813 Fax: 845-365-8156
>>>>> =====================================
>>>>
>>>>
>>>
>>>
>>> --
>>> =====================================
>>> Eunseo Choi
>>> Post-Doctoral Research Scientist
>>>
>>> Lamont-Doherty Earth Observatory
>>> 305C Oceanography
>>> P.O. Box 1000
>>> 61 Rt. 9W
>>> Palisades, NY 10964-8000
>>>
>>> http://www.ldeo.columbia.edu/~echoi
>>> Phone: 845-365-8813 Fax: 845-365-8156
>>> =====================================
>>
>>
>
>
> --
> =====================================
> Eunseo Choi
> Post-Doctoral Research Scientist
>
> Lamont-Doherty Earth Observatory
> 305c Oceanography
> P.O. Box 1000
> 61 Rt. 9W
> Palisades, NY 10964-8000
>
> http://www.ldeo.columbia.edu/~echoi
> Phone: 845-365-8813 Fax: 845-365-8156
> =====================================
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