<HTML>
<HEAD>
<TITLE>Problems Extruding a structured 2D mesh - transfinite OK on 2D, fails in 3D</TITLE>
</HEAD>
<BODY>
<FONT FACE="Calibri, Verdana, Helvetica, Arial"><SPAN STYLE='font-size:11pt'>I have made a 2D mesh consisting of 24 transfinite surfaces (structured grid). It meshes perfectly when I click on 2D on the gmsh GUI.<BR>
<BR>
However, when I add the command to extrude (1 layer) the 2D mesh to a flat 3D mesh for use in OpenFOAM, the first nine surfaces and the last surface are meshed in a structured way (extruded properly), but from surface 10-23, the 3D transfinite extrusin fails and the structured transfinite grids are replaced by unstructured meshes. <BR>
<BR>
This is my extrusion command:<BR>
<BR>
**********<BR>
Extrude {0,0,0.01} <BR>
{<BR>
Surface{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24}; <BR>
Layers{1}; <BR>
Recombine; <BR>
}<BR>
**********<BR>
<BR>
All 24 surfaces are created the same way with identical n0menclature such as for surface 23:<BR>
<BR>
**********<BR>
// Upstream upper wake region - SURFACE 23<BR>
Line(80) = {17,33};<BR>
Line(81) = {33,34};<BR>
Line(82) = {34,18};<BR>
Circle(83) = {18, 201, 17};<BR>
Transfinite Line {80} = N80 Using Progression B80;<BR>
Transfinite Line {81} = N81 Using Progression B81;<BR>
Transfinite Line {-82} = N82 Using Progression B82;<BR>
Transfinite Line {83} = N83 Using Progression B83;<BR>
Line Loop(23) = {80, 81, 82, 83};<BR>
Plane Surface(23) = {23};<BR>
Transfinite Surface {23} = {17,33,34,18};<BR>
Recombine Surface {23};<BR>
**********<BR>
<BR>
One point I should make is that some lines share points with other lines and some lines lie on top of other lines using the same points to define them. I did this to ensure that the transfinite interpolation on the surfaces that are separated by these lines is unique for each surface.<BR>
<BR>
I cannot include the entire grid since it is of a confidential nature; can anyone shed light onto this problem with this limited information?<BR>
<BR>
Thank you!<BR>
<BR>
Dr. Johannes N. Theron<BR>
Proprietor<BR>
<B>KanoeFabrik<BR>
</B>4 Le Roux St.<BR>
De Rust, 6650<BR>
South Africa<BR>
+27 (79) 166-0742<BR>
www.kanoefabrik.com<BR>
<a href="jan@kanoefabrik.com">jan@kanoefabrik.com</a><BR>
<a href="http://www.facebook.com/people/Kanoe-Fabrik/100001483291810">http://www.facebook.com/people/Kanoe-Fabrik/100001483291810</a><BR>
<BR>
<BR>
<BR>
<BR>
</SPAN></FONT>
</BODY>
</HTML>