<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>Le 11 déc. 2013 à 11:53, George Ntemos <<a href="mailto:george.ntemos11@imperial.ac.uk">george.ntemos11@imperial.ac.uk</a>> a écrit :</div><br class="Apple-interchange-newline"><blockquote type="cite">
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charset=ISO-8859-1"><p style="margin-bottom: 0cm">Dear Gmsh Development Team,<br>
<br>
<br>
My
name is George Ntemos and I am a PhD student in the Aeronautics
Department of Imperial College London. Our team is developing and
applying CFD software, using gmsh for high-order meshing purposes.</p><p style="margin-bottom: 0cm">I am currently studying a flow case
around a rod-aerofoil set-up and I've been experiencing some
problems
with high-order meshing. More specifically, the meshing algorithm
fails to mesh in high order around the (spline-defined) aerofoil
profile. Please find attached a lightweight .geo file of my
configuration just for demonstration purposes. If one tries
meshing
this file in 3d and for order > 1, gmsh will warn that, to my
understanding, the algorithm fails to properly converge at certain
points, visibly resulting in quite severe discrepancies for a few
elements (curvilinear on). It also warns that it cannot orient the
normal for the two extruded surfaces of the rod (cylinder)
boundary
layer. It is worth noting here that I am experiencing none of the
above problems when I am meshing in 2d. Since my 3d mesh is just a
simple extrusion, I would assume that extending to 3d is just a
trivial case of translating every operation along the 3<sup>rd</sup>
dimension. I am of course not particularly experienced in using
gm</p></div></blockquote><div><br></div><div>The 2D mesh is already wrong as is. If you use the high order tools with the current parameters, this</div><div>is what it gives : </div><div><br></div><div><div>Info : --- Optimization pass with initial jac. range (-0.528961, 1.76584), jacBar = -0.581857</div><div>Info : Reached jacobian (0.148494 1.77654) requirements, setting null gradient</div><div>Info : Optimization finalized after 11 iterations (41 function evaluations),</div><div>Info : because gradient norm is no more than EpsG</div><div>Info : Optimization done Range (0.148494,1.77654)</div><div>Info : Optimization succeeded</div><div>Info : Done optimizing high order mesh (278.816 s)</div><div><br></div></div><div>It is quite long indeed (work clearly in progress for boundary layers) but it worked !</div><div><br></div><div>JF</div><br><blockquote type="cite"><div bgcolor="#FFFFFF" text="#000000"><p style="margin-bottom: 0cm">sh
however and I may very well be missing something here.</p><p style="margin-bottom: 0cm">Any help regarding these issues would
be greatly appreciated.</p><p style="margin-bottom: 0cm">Thank you for your time.</p><p style="margin-bottom: 0cm"><br>
</p><p style="margin-bottom: 0cm">Best regards,</p><p style="margin-bottom: 0cm">George</p>
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<span><rod_aerofoil_3d_light.geo></span>_______________________________________________<br>gmsh mailing list<br><a href="mailto:gmsh@geuz.org">gmsh@geuz.org</a><br>http://www.geuz.org/mailman/listinfo/gmsh<br></blockquote></div><br><div apple-content-edited="true">
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