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Hi Jon,</div>
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Can you give a little more info? Are you using the USM solver? Are you using AMR? Have you actually checked that divB>0 in the output data? A log file from a representative run would be useful.</div>
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In my experience, the USM solver in cylindrical R-Z coordinates with AMR can be….touchy. But it should work and maintain divB=0! (See, e.g., <a href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013ApJ...773..136J&link_type=EJOURNAL">http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013ApJ...773..136J&link_type=EJOURNAL</a>).</div>
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Cheers,</div>
<div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">
Sean</div>
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Sean M. Couch</div>
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Assistant Professor<br>
Department of Physics and Astronomy<br>
Department of Computational Mathematics, Science, and Engineering<br>
National Superconducting Cyclotron Laboratory/Facility for Rare Isotope Beams<br>
Michigan State University<br>
567 Wilson Rd, 3250 BPS<br>
East Lansing, MI 48824<br>
(517) 884-5035 —— <a href="mailto:couch@pa.msu.edu">couch@pa.msu.edu</a> —— <a href="http://www.pa.msu.edu/~couch">www.pa.msu.edu/~couch</a></div>
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<p class="airmail_on">On May 25, 2017 at 4:41:45 PM, Slavin, Jonathan (<a href="mailto:jslavin@cfa.harvard.edu">jslavin@cfa.harvard.edu</a>) wrote:</p>
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Hi all,</div>
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I'm running MHD simulations where I set off a second supernova explosion within a pre-existing remnant. I'm using Simulation_adjustEvolution for this. However, I'm running into a problem with the magnetic field just after initiating the second explosion.
I'm getting very large pixel-to-pixel variations in Bx and By at the edge of the new expanding blast wave. I'm thinking that it could be because of non-zero div B in the region in which the explosion is generated. So my question is, does anyone have a suggestion
for div B cleaning at the point that the explosion is started, i.e. within Simulation_adjustEvolution, to prevent the problems I'm having? I don't really expect the B field to be dynamically important inside the remnant (beta >> 1), so accuracy of the B field
is probably not important there. I should add that I'm doing these calculations in 2D cylindrical symmetry (R-Z). Thanks in advance for any help.</div>
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Regards,</div>
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Jon</div>
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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>
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