[Nek5000-users] solver tolerances and norm of residual

[nek5000-users at lists.mcs.anl.gov]

Hi Alex,

I just tried your case - it ran w/o any difficulty.

I wonder if there is an issue w/ your SIZE file?  I've
placed the one that I used in

www.mcs.anl.gov/~fischer/SIZE

which you can just grab.  Then makenek 3dtest followed by
the usual run process.... Let me know if this resolves the
issue for you.

Cheers,

Paul F.


On Tue, 16 Nov 2010, nek5000-users at lists.mcs.anl.gov wrote:

> Hi,
>
> I think this is not the reason because in a previous attempt to face the
> 3D problems I tried to solve the 3D lid-driven cavity (no periodic BC) and
> I obtained the same error: NaN in Helholtz residual.
>
> Maybe I should start from the turbChannel example and simplify the problem
> to reach a laminar 3D poiseuille flow.
>
> Anyway, thanks a lot for your answers.
>
>> A quick look of the *rea file did not bring up anything.  I recall an
>> issue with periodic BC's, following is an email from one of the
>> developers:
>>
>>
>> Hi Frank,
>>
>> Yes -- we currently don't support periodic bcs for
>> anything smaller than a 3 x 3 x 3 array of elements.
>>
>> There's a technical reason for this --- it can be
>> circumvented if really needed, but it would not
>> fit within the std. context.
>>
>> Sorry about that.
>>
>> Paul
>>
>> On Tue, 2010-11-16 at 12:56 -0500, nek5000-users at lists.mcs.anl.gov
>> wrote:
>>> Hi Frank,
>>>
>>> The rea file has been attached.
>>> Meanwhile I'll check the BC...
>>>
>>> Thanks
>>>
>>>> Hello Alex,
>>>>
>>>> I looked through your files & didn't see anything amiss (by the way,
>>> it
>>>> would be best to post your *.rea file).  Since it blows up on the
>>> first
>>>> attempt to solve for pressure, perhaps the BC's don't satisfy
>>>> conservation of mass?
>>>>
>>>> Cheers,
>>>> Frank
>>>>
>>>>
>>>>
>>>> On Tue, 2010-11-16 at 11:40 -0500, nek5000-users at lists.mcs.anl.gov
>>>> wrote:
>>>>
>>>>> Hi Nek users,
>>>>>
>>>>> I am new in using Nek5. I have succesfully simualted the lid-driven
>>>>> flow,
>>>>> rayleigh-bénard in a square cavity and laminar poiseuille flow.
>>> All of
>>>>> them were 2d cases. I though it would be straightforward to move from
>>> 2D
>>>>> to 3D simualtions but I have not been able to run a 3D poiseuille
>>>>> channel.
>>>>> I am obtaining an error on Helmoltz solver even in the first
>>> iteration.
>>>>>
>>>>> Please, find output, usr and box files attached.
>>>>> Thanks in advance.
>>>>>
>>>>> ..........................................
>>>>>            Alex Fabregat
>>>>>         Post-doctoral fellow
>>>>>         University of Ottawa
>>>>> Department of Mechanical Engineering
>>>>> _______________________________________________
>>>>> Nek5000-users mailing list
>>>>> Nek5000-users at lists.mcs.anl.gov
>>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>>
>>>> --
>>>> Frank Herbert Muldoon, Ph.D. Mechanical Engineering
>>>> Technische Universität Wien (Vienna University of Technology)
>>>> Inst. f. Strömungsmechanik und Wärmeübertragung (Institute of
>>> Fluid
>>>> Mechanics and Heat Transfer)
>>>> Resselgasse 3
>>>> 1040 Wien
>>>> Tel: +4315880132232
>>>> Fax: +4315880132299
>>>> Cell:+436765203470
>>>> fmuldoo (skype)
>>>> http://tetra.fluid.tuwien.ac.at/fmuldoo/public_html/webpage/frank-muldoon.html
>>>> _______________________________________________
>>>> Nek5000-users mailing list
>>>> Nek5000-users at lists.mcs.anl.gov
>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>>
>>>
>>>
>>> ..........................................
>>>            Alex Fabregat
>>>         Post-doctoral fellow
>>>         University of Ottawa
>>> Department of Mechanical Engineering
>>> _______________________________________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.gov
>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>> --
>> Frank Herbert Muldoon, Ph.D. Mechanical Engineering
>> Technische Universität Wien (Vienna University of Technology)
>> Inst. f. Strömungsmechanik und Wärmeübertragung (Institute of Fluid
>> Mechanics and Heat Transfer)
>> Resselgasse 3
>> 1040 Wien
>> Tel: +4315880132232
>> Fax: +4315880132299
>> Cell:+436765203470
>> fmuldoo (skype)
>> http://tetra.fluid.tuwien.ac.at/fmuldoo/public_html/webpage/frank-muldoon.html
>>
>> _______________________________________________
>> Nek5000-users mailing list
>> Nek5000-users at lists.mcs.anl.gov
>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>
>
>
> ..........................................
>           Alex Fabregat
>        Post-doctoral fellow
>        University of Ottawa
> Department of Mechanical Engineering
>
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> Nek5000-users at lists.mcs.anl.gov
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>