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Hi Jon,</div>
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I think you could have also simply set the runtime parameter `dtmax` equal to `dtinit`, or some other small value, to achieve this in a simpler way without editing the code.</div>
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<div id="bloop_sign_1496847266096630016" class="bloop_sign">Cheers,
<div>Sean</div>
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<p class="airmail_on">On June 7, 2017 at 9:37:19 AM, Slavin, Jonathan (<a href="mailto:jslavin@cfa.harvard.edu">jslavin@cfa.harvard.edu</a>) wrote:</p>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">
Hi all,</div>
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<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">
Just thought that I'd let you know that I got my multiple explosion runs working. What made all the difference is setting the time step to a very small value, I used the initial dt value. So this involved adding</div>
<div class="gmail_default"><font face="arial, helvetica, sans-serif">use Driver_data, ONLY : dr_dtInit</font><br>
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<div class="gmail_default"><font face="arial, helvetica, sans-serif">and changing the declaration of dt to</font></div>
<div class="gmail_default"><font face="arial, helvetica, sans-serif">real, intent(inout) :: dt<br>
</font></div>
<div class="gmail_default"><font face="arial, helvetica, sans-serif">(Can one change a value of a variable declared intent(in)?)</font></div>
<div class="gmail_default"><font face="arial, helvetica, sans-serif">and then when the explosion is initiated setting dt = dr_dtInit</font></div>
<div class="gmail_default"><font face="arial, helvetica, sans-serif">So all the issues of large B fluctuations was due to the overly large time step at the moment the explosion is initiated.</font></div>
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<div class="gmail_default"><font face="arial, helvetica, sans-serif">Jon</font></div>
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<div class="gmail_quote">On Mon, Jun 5, 2017 at 4:22 AM, Joshua Wall <span dir="ltr">
<<a href="mailto:joshua.e.wall@gmail.com" target="_blank">joshua.e.wall@gmail.com</a>></span> wrote:<br>
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<div dir="ltr">Hello Jon and Klaus,
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<div> I have been thinking about guard cell filling in Jon's problem (and I'm also tracking down a bug at the moment I think is related to gc filling) and perhaps have hit on something. So I wanted to check with Klaus and see if this is correct.</div>
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<div> I see in the call for Grid_fillGuardCells.F90 right at the top:</div>
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<div><font face="monospace"> !We can skip this guard cell fill if the guard cells are up to date.</font></div>
<div><font face="monospace"> if (gridDataStruct /= WORK) then</font></div>
<div><font face="monospace"> skipThisGcellFill = gr_gcellsUpToDate</font></div>
<div><font face="monospace"> else</font></div>
<div><font face="monospace"> skipThisGcellFill = .false.</font></div>
<div><font face="monospace"> end if</font></div>
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<div>This looks to me like if I haven't called:</div>
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<div><font face="monospace">call Grid_notifySolnDataUpdate( (/ EINT_VAR, DENS_VAR, ENER_VAR /) )</font><br>
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That silently the guard cell filling call will be ignored if they were filled just before my routine modified variables without notifying the Grid unit. Is that correct Klaus?</div>
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<div>If so, this may also be Jon's error.</div>
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<div>Cordially,</div>
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<div>Josh</div>
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<div dir="ltr">On Wed, May 31, 2017 at 12:01 AM Klaus Weide <<a href="mailto:klaus@flash.uchicago.edu" target="_blank">klaus@flash.uchicago.edu</a>> wrote:<br>
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On Fri, 26 May 2017, Joshua Wall wrote:<br>
<br>
> Hello Jon,<br>
><br>
> There's two ways to do the EOS update. One is to call Eos_wrapped at<br>
> the end of the block loop on each block you update as you go through the<br>
> loop. Make sure you pass which mode you want based on the variables you<br>
> updated, which here sounds like pressure and internal energy.<br>
<br>
That's usually the way to do it.<br>
<br>
> So that would<br>
> look something like:<br>
><br>
><br>
> do blk=1, numBlocks<br>
><br>
> blockID = blockList(blk)<br>
><br>
> call Grid_getBlkLimits(blockID, blkLimits, blkLimitsGC)<br>
><br>
> call Grid_getBlkPtr(blockID, solnData)<br>
> do i<br>
> do j<br>
> do k<br>
><br>
> solnData(DENS_VAR,i,j,k) = stuff<br>
> solnData(EINT_VAR,i,j,k) = stuff<br>
<br>
To make sure the Eos_wrapped call below does not get confused,<br>
one should also modify ENER_VAR when modifying EINT_VAR.<br>
Usually by adding the same amount to both variables.<br>
(Even more variables should be modified if using 3T Hydro<br>
and Eos.)<br>
<br>
><br>
> end do<br>
> end do<br>
> end do<br>
><br>
> call Eos_wrapped(MODE_DENS_EI, blkLimits, blockID)<br>
><br>
> end do<br>
><br>
> The other way to do it is to:<br>
><br>
> call Grid_fillGuardCells(CENTER, ALL_DIR, LEAF, doEos=.true.,<br>
> eosMode=MODE_DENS_EI)<br>
<br>
1. This call is not valid as written, or at least extremely confusing.<br>
I assume the "LEAF" is meant as a value for the (optional)<br>
"selectBlockType" dummy argument; if that is true, the call should be<br>
written as<br>
<br>
| call Grid_fillGuardCells(CENTER, ALL_DIR, selectBlockType=LEAF,<br>
| doEos=.true.,eosMode=MODE_<wbr>DENS_EI)<br>
<br>
Otherwise the compiler will interpret it as ...,minLayers=LEAF,...,<br>
which is probably not intended.<br>
<br>
1. This call does *not* apply the Eos to interior cells, but only to<br>
(some) guard cells. In some previous version of FLASH, the doEos may have<br>
applied to all cells (interior+guard), but that has not been the case<br>
for several releases. Now the Eos is only applied to guard cells that<br>
correspond to neighboring blocks at a different refinement.<br>
<br>
> This method ensures that whatever happens next, not only is the EOS updated<br>
> all values for each cell, *but also those values are valid in guard cells<br>
> on other processors*. I mention this method because using the Eos_wrapped<br>
> and forgetting to fill guard cells after has been a "gotcha" moment for me<br>
> in the past, and was a very tricky error to track down. But guard cell<br>
> filling is also expensive, so if you know its safe to not do it,<br>
> Eos_wrapped is the way to go.<br>
<br>
The general rule should be:<br>
<br>
* call Eos_wrapped at the end of your code, if you have modified any<br>
variables that could make the thermodynamic state inconsistent;<br>
* call Grid_fillGuardCells at the beginning of your code if you need<br>
to refer to any variables in guard cells - with or without doEos<br>
depending on the needs of your code.<br>
<br>
unless you *really* understand the consequences of deviating from this<br>
convention.<br>
<br>
Klaus<br>
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<div>Joshua Wall<br>
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Doctoral Candidate<br>
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Department of Physics<br>
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Drexel University<br>
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3141 Chestnut Street<br>
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Philadelphia, PA 19104<br>
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<div dir="ltr">________________________________________________________<br>
Jonathan D. Slavin Harvard-Smithsonian CfA<br>
<a href="mailto:jslavin@cfa.harvard.edu" target="_blank">jslavin@cfa.harvard.edu</a> 60 Garden Street, MS 83<br>
phone: (617) 496-7981 Cambridge, MA 02138-1516<br>
cell: (781) 363-0035 USA<br>
________________________________________________________<br>
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