<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><span data-mce-bogus="1" data-mce-type="format-caret"><span data-mce-bogus="1" data-mce-type="format-caret"><strong></strong></span></span><div><div><div>Dear <span id="DWT1260" class="ZmSearchResult"><span id="DWT1266" class="ZmSearchResult">FLASH</span></span> Code users,<br></div><br><div>In the <span id="DWT1262" class="ZmSearchResult"><span id="DWT1268" class="ZmSearchResult">FLASH</span></span> version 4.6.2 there is two <span id="DWT1663" class="ZmSearchResult"><span id="DWT1671" class="ZmSearchResult">Biermann</span></span> battery test cases. <br></div><div>One in 2D cartesian geometry and one in 2D axis-symmetric (cylindrical) geometry.</div><br><div><strong>1-</strong> Whatever in 2D Cartesian or 2D axis-symmetric cases: the magnetic z component is the same.<br></div><div>And there is no magnetic field variation whatever I activated the</div><div>"source BB terms" or the "3T BB term": i.e in flash.par:<br></div><div>(use_Biermann3T = .false. hy_biermannSource = .true.</div><div>or use_Biermann3T = .true. hy_biermannSource = .false.)<br></div><div>The z component values of the magnetic field magz are the same. <strong>This behavior is correct.</strong><br></div><br><div><strong>-However it seems that the SIGN of the magz component is not correct in 2D axis-symmetric case (it is the opposite).</strong><br></div><div><strong>Are you agree with that?</strong><br></div><br><div><strong>2- </strong>I did the same test case in <strong>3D geometry</strong> with the the same temperature and density profile.<br></div><br><div>When I deactivated the source term </div><div>i.e. <strong>use_Biermann3T = .true. hy_biermannSource = .false.</strong> in the flash.par<br></div><div>The values of <strong>magz</strong> seems correct (if we compare with the 2D previous cases)</div><div><strong> BUT</strong><br></div><div>When Biermann source term is activated:</div><div>i.e. <strong>use_Biermann3T = .false.</strong> <strong>hy_biermannSource = .true.</strong> in flash.par</div><div><strong>then now the magz values are very different and very low (20 times lower).</strong><br></div><br><div><strong>-I don't know why there is a discrepancy between these two 3D simulations</strong> <br></div><br><div>I hope you can help to understand what happens.<br></div><br><div>Best regards,<br></div><br><div>Xavier Ribeyre</div></div><br></div><div><br data-mce-bogus="1"></div></div><br></div></div></body></html>