<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2900.6400" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>I am running GMSH to produce the tet mesh around a
closed ended circular cylinder at 135 degrees angle of incidence to use in a CFD
simulation. I use a STL file to define the cylinder triangular surface.
The outer boundary of the volume is a six faced box.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>GMSH produces a tet mesh around the scylinder
inside the box but outputs a message "NN illegal tets are still in the
mesh" where NN is a number depending on the number of triangles in the STL
file. How does GMSH decide a tet is an "illegal tet"
?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For other cases, GMSH also outputs the message "NN
points could not be inserted". NN is again a number. Is there any way
to find out why there are problems with these points and where they are
?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For these, I can send you my STL and GEO files if
that will help.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Finally, because I'm trying CFD mesh generation
cases, I'm trying to limit the volume of the mesh to say one half of the
body as the problem has a plane of symmetry. I'm trying to use the
Compound Line to define the geometry edge profile where the profile
may be made up of 100 points. Is there any restriction on the number of
points that can make up a compound line ? Even though its only
a cylinder, I need that number of points to get the tets near to the surface to
be quite small to resolve the flow solution.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Any help would be gratefully received.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Many thanks</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Steve Daley</FONT></DIV></BODY></HTML>