<html><body><div>Dear gmsh list,</div><div><br data-mce-bogus="1"></div><div>firstofall, thanks for your help in the past. Currently I am working on a 2-D curved surface with a low-Re boundary layer mesh. When I am trying to extrude it in the third dimension I keep getting the error "<span style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;" data-mce-style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;"> Warning: Could not orient normal of surface 37". This occurs only when I have a huge amount of cells (like 40) in the normal direction. Below you can see the minimal example. I would appreciate any advice.</span></div><div><span style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;" data-mce-style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;"><br data-mce-bogus="1"></span></div><div><span style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;" data-mce-style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;">Best regards,</span></div><div><span style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;" data-mce-style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;"><br data-mce-bogus="1"></span></div><div><span style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;" data-mce-style="color: #000000; font-family: SFNSText, 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300; letter-spacing: normal; line-height: 22.5px; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: #ffffff;">Kate</span></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>//Gmsh<br><br>radius=1;<br>outerradius=1.5;<br>extr=0.1; // Extrusion-length<br><br>// Points<br>Point(1)={radius,0,0};<br>Point(2)={radius*Cos(45*Pi/180),radius*Sin(45*Pi/180),0};<br>Point(3)={outerradius,0,0};<br>Point(4)={outerradius*Cos(45*Pi/180),outerradius*Sin(45*Pi/180),0};<br>Point(5)={0,0,0}; // Center<br><br>// Normal Lines:<br>Line(10)={1,3};<br>Line(11)={2,4};<br><br>/////////////////////////////////////////////////////////////////////////////////<br>Transfinite Line {10,11} = 40 Using Progression 1.2; // 10 layers: working // 40 layers: Warning: Could not orient normal of surface 37<br>/////////////////////////////////////////////////////////////////////////////////<br><br>// Curved Lines:<br>Circle(12) = {1, 5, 2};<br>Circle(13) = {3, 5, 4};<br>Transfinite Line {12,13} = 10;<br><br>// Transfinite Surface:<br>Line Loop(14) = {10, 13, -11, -12};<br>Plane Surface(15) = {14};<br>Transfinite Surface {15};<br>Recombine Surface {15};<br></div><div><br data-mce-bogus="1"></div><div>//Extrusion:<br>Extrude {0, 0, extr} {Surface{15}; Layers{1}; Recombine;}<br><br></div></body></html>