[FLASH-USERS] restart PM run in UG mode

[Alexander Wagner]

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
>>
>>
>>