[FLASH-USERS] [EXTERNAL] Re: Use of implicit diffusion solver with AMR

[Madhav Nagori]

Hi,

Thanks for a quick reply. Please find attached the log file and the
amr_runtime_parametrs.dump from the run which blows up. Please let me know
if there are any recommendations.

I am using a split solver because it was giving more accurate results.

Thank you for taking the time to understand my problem setup.


On Tue, Apr 25, 2023 at 8:48 PM Adam Reyes <adam.reyes at rochester.edu> wrote:

> Hi Madhav,
>
> That specific error that you shared is more of a warning and just means
> that the code won't be able to report reliable timing information for the
> "PFFT_Init". If possible could you share a logfile from the run that blows
> up? This would provide more information about how your problem is setup and
> if anything could be recommended.
>
> Admittedly I don't have much experience with the multigrid solvers, but
> maybe someone who does could be of more help. Is there a reason that you're
> using the split solver? The unsplit solver with HYPRE is a bit more used
> for diffusion.
>
> *************************************************************************
> Adam Reyes
>
> Code Group Leader, Flash Center for Computational Science
> Research Scientist, Dept. of Physics and Astronomy
> University of Rochester
> River Campus: Bausch and Lomb Hall, 369
> 500 Wilson Blvd. PO Box 270171, Rochester, NY 14627
> Email adam.reyes at rochester.edu
> Web https://flash.rochester.edu
>  (he / him / his)
>
> *************************************************************************
>
> On Tue, Apr 25, 2023 at 5:36 PM Madhav Nagori <mnagori at uncc.edu> wrote:
>
>> Thank you very much for your reply. I have been trying to use the
>> implicit diffusion with AMR, but I am not able to run it. I am getting the
>> following error and then my solution diverges and blows up.
>>
>> *perfmon: ran out of space for timer, "PFFT_Init", cannot time this timer
>> with perfmon*
>>
>> What I did was that I added the multigrid solver (REQUESTS
>> Grid/GridSolvers/Multigrid/PfftTopLevelSolve/) to my Config file and added
>> the corresponding runtime parameters in my *.par file* according to the
>> FLASH manual. Is there anything else that needs to be added ? Kindly let me
>> know.
>>
>> P.S: I am using the split solver which means that the time advancement
>> code is solved by Thomas Algorithm. Would this have any connection with
>> this error?
>>
>> Thank you for your time.
>>
>> On Wed, Apr 5, 2023 at 7:09 PM Hansen, Eddie <ehansen at pas.rochester.edu>
>> wrote:
>>
>>> The user guide is referring to implicit magnetic diffusion. That one is
>>> not yet supported for AMR. Currently, the implicit diffusion solvers with
>>> AMR are for thermal conduction and radiation only.
>>>
>>> ******************************************
>>> Eddie Hansen | Research Scientist
>>> Flash Center for Computational Science
>>> Dept. of Physics and Astronomy
>>> University of Rochester, Rochester, NY
>>> Cell 607-341-6126 | flash.rochester.edu
>>> (he / him / his)
>>> ******************************************
>>> ------------------------------
>>> *From:* flash-users <flash-users-bounces at flash.rochester.edu> on behalf
>>> of Madhav Nagori <mnagori at uncc.edu>
>>> *Sent:* Wednesday, April 5, 2023 10:31:48 AM
>>> *To:* flash-users at flash.rochester.edu <flash-users at flash.rochester.edu>
>>> *Subject:* [FLASH-USERS] Use of implicit diffusion solver with AMR
>>>
>>> Hello FLASH users and Development Team,
>>>
>>> I want to use the implicit diffusion solver for some very high
>>> resolution cases of cell size 512*512*2048. For such high resolution, I
>>> want to use AMR as the uniform mesh will take months to run.
>>>
>>> The user guide tells that the paramesh is not available to the implicit
>>> diffusion solver. Is it possible to modify the code so that I can run with
>>> AMR?
>>>
>>> P.S: I am using mass diffusion, viscosity diffusion and thermal
>>> diffusion in my simulation. I tried using the explicit diffusion solver
>>> (Flux Based Diffusion) with AMR, but that gave wrong results. However, the
>>> implicit solver is providing the correct results.
>>>
>>> Please let me know.
>>>
>>> Thank You
>>>
>>> --
>>> Best Regards,
>>>
>>> Madhav Nagori
>>>
>>> PhD Candidate | Laboratory for Multiscale Computational Fluid Dynamics
>>> Department of Mechanical Engineering and Engineering Sciences
>>> University of North Carolina at Charlotte
>>> Office: Duke 273, 9330 Robert D. Snyder Rd, Charlotte, NC 28262, USA
>>> Email: mnagori at uncc.edu
>>> LinkedIn: www.linkedin.com/in/madhav-nagori
>>>
>>
>>
>> --
>> Best Regards,
>>
>> Madhav Nagori
>>
>> PhD Candidate | Laboratory for Multiscale Computational Fluid Dynamics
>> Department of Mechanical Engineering and Engineering Sciences
>> University of North Carolina at Charlotte
>> Office: Duke 273, 9330 Robert D. Snyder Rd, Charlotte, NC 28262, USA
>> Email: mnagori at uncc.edu
>> LinkedIn: www.linkedin.com/in/madhav-nagori
>> _______________________________________________
>> flash-users mailing list
>> flash-users at flash.rochester.edu
>>
>> For list info, including unsubscribe:
>> https://flash.rochester.edu/mailman/listinfo/flash-users
>>
>

-- 
Best Regards,

Madhav Nagori

PhD Candidate | Laboratory for Multiscale Computational Fluid Dynamics
Department of Mechanical Engineering and Engineering Sciences
University of North Carolina at Charlotte
Office: Duke 273, 9330 Robert D. Snyder Rd, Charlotte, NC 28262, USA
Email: mnagori at uncc.edu
LinkedIn: www.linkedin.com/in/madhav-nagori
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20230425/acbfe77a/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: amr_runtime_parameters.dump
Type: application/octet-stream
Size: 1044 bytes
Desc: not available
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20230425/acbfe77a/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: RRTI_2D_case12_uptbd_amr.log
Type: text/x-log
Size: 39296 bytes
Desc: not available
URL: <http://flash.rochester.edu/pipermail/flash-users/attachments/20230425/acbfe77a/attachment.bin>