[FLASH-USERS] restart PM run in UG mode

Tomasz Plewa tplewa at fsu.edu
Wed Mar 31 07:46:58 EDT 2010


Alexander -

I see. I do not know of too many FLASH RHD unit applications. Perhaps 
some real debugging is due.

Again, since all the information is readily available, it seems like the 
code restart logic is broken.

Tomek
--
Alexander Wagner wrote:
> Hi Tomek,
>
> After setting convertToConsvdInMeshInterp = .false. I still get the error
>
> [Eos_wrapped] ERROR Density or Internal Energy are zero after a call to EOS!
> [ 03-31-2010  18:34:31.188 ] [DRIVER_ABORT]: Driver_abort() called by PE
>
> Though not anymore the warning
>
> WARNING after gc filling: min. unk(DENS_VAR)=0.000000000000000000000  
> PE=219   block=83 type=2    [...]
>
> I was able to dump a checkpoint file but when restarting with that 
> checkpoint file (and nrefs=0), I get the same problems, that is, there 
> are regions with 0 values in the mesh.
>
> I'm going to inspect the checkpointfile with VisIt, but it seems some 
> debugging is necessary.
>
> It is perhaps also worth mentioning that I'm using the RHD unit. Can you 
> think of a reason that this trick might not work with the RHD unit.
>
> Many thanks for your help so far!
> Alex
>
>
> Tomasz Plewa wrote:
>   
>> Erm... Your mesh contains enough information and so that should never 
>> happen. It seems like a bug to me, possibly a broken code logic.
>>
>> Try setting
>>
>> convertToConsvdInMeshInterp     = .false.
>>
>> If that does not help (perhaps to overcome broken logic), one would 
>> need to debug the code.
>>
>> Tomek
>> -- 
>> Alexander Wagner wrote:
>>     
>>> Hi Tomek,
>>>
>>> I tried your suggested method but portions of the grid get filled 
>>> with 0s when I restart with lrefine_min=lrefine_max.
>>>
>>>
>>>  iteration, no. not moved =            0      191394
>>>  iteration, no. not moved =            1       77989
>>>  iteration, no. not moved =            2           0
>>> ...skipping...
>>> refined: total leaf blocks =       202952
>>> refined: total blocks =       231945
>>> INFO: Grid_fillGuardCells is ignoring masking.
>>> WARNING after gc filling: min. 
>>> unk(DENS_VAR)=0.000000000000000000000          PE=219   
>>> block=83                               type=2    [...]
>>>
>>>
>>> DRIVER_ABORT:
>>> [Eos_wrapped] ERROR Density or Internal Energy are zero after a call 
>>> to EOS!
>>>
>>> What am I doing wrong?
>>> Cheers,
>>> Alex
>>>
>>>
>>>
>>> Tomasz Plewa wrote:
>>>  
>>>       
>>>> The simplest way of eliminating most of the AMR overhead is to set
>>>> lrefine_min=lrefine_max upon restart, dump a checkpoint after the first
>>>> mesh refinement, and restart again but now with nrefs=0.
>>>>
>>>> It will not be as fast as real UG, but estimating possible gains is not
>>>> straightforward. If I remember correctly and for simple hydro, the 
>>>> above
>>>> approach offers gains provided the filling factor exceeds about 0.3.
>>>>
>>>> Tomek
>>>> -- 
>>>> On 3/29/2010 7:49 PM, Alexander Wagner wrote:
>>>>      
>>>>         
>>>>> Dear FLASH developers/users,
>>>>>
>>>>> Just a quick question, as I can't find the answer in the manual or
>>>>> mailing list archive;
>>>>>
>>>>> Is it possible to restart an AMR simulation in UG mode with a
>>>>> checkpoint file created in PM mode? Or does it involve starting a new
>>>>> run and reading in the initial conditions from the checkpoint file
>>>>> manually.
>>>>>
>>>>> I can imagine this being a scenario commonly required when the flow in
>>>>> a simulation (especially in 3D) becomes more complex and fills larger
>>>>> portions of the domain; at some point most of the domain is maximally
>>>>> refined and the overhead in AMR exceeds the advantages of using AMR.
>>>>>
>>>>> Many thanks,
>>>>> Alex
>>>>>
>>>>>
>>>>>           
>>>>>           
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