<div dir="ltr">Hi everyone,<div><br></div><div>Recently, I am trying to generate a simple mixed mesh using Gmsh. The domain consists of 2 volumes. I want the first volume is unstructured and it consists of Hexahedons only. The second volume consists of whatever mixed cells, like Tetrahedron, Prism, Pyramid, Hexahedron.</div><div><br></div><div> <img src="cid:ii_jfpshypv0_162a1a52369d9e98" width="224" height="239" style="margin-right: 0px;"></div><div><br></div><div>Here is my .geo file:</div><div><div>// generate a mixed mesh </div><div>lc = 0.3;</div><div><br></div><div>nx=10;</div><div>ny=10;</div><div>nz=3;</div><div><br></div><div>hd=5; //half width</div><div>Point(1) = {-hd, -hd, -hd/2, lc}; </div><div>Point(2) = {hd, -hd, -hd/2, lc}; </div><div>Point(3) = {hd, hd, -hd/2, lc}; </div><div>Point(4) = {-hd, hd, -hd/2, lc}; </div><div>Point(5) = {-hd, -hd, hd/2, lc}; </div><div>Point(6) = {hd, -hd, hd/2, lc}; </div><div>Point(7) = {hd, hd, hd/2, lc}; </div><div>Point(8) = {-hd, hd, hd/2, lc};</div><div><br></div><div>Point(9) = {-hd, -hd, hd/2+hd, lc}; </div><div>Point(10) = {hd, -hd, hd/2+hd, lc}; </div><div>Point(11) = {hd, hd, hd/2+hd, lc}; </div><div>Point(12) = {-hd, hd, hd/2+hd, lc};</div><div><br></div><div>Line(1) = {4,3};</div><div>Line(2) = {3,2};</div><div>Line(3) = {2,1};</div><div>Line(4) = {1,4};</div><div>Line(6) = {5,6};</div><div>Line(7) = {6,7};</div><div>Line(8) = {7,8};</div><div>Line(9) = {8,5};</div><div>Line(10) = {1,5};</div><div>Line(11) = {4,8};</div><div>Line(12) = {2,6};</div><div>Line(13) = {3,7};</div><div><br></div><div>Line(14) = {8,12};</div><div>Line(15) = {7,11};</div><div>Line(16) = {6,10};</div><div>Line(17) = {5,9};</div><div>Line(18) = {12,11};</div><div>Line(19) = {11,10};</div><div>Line(20) = {10,9};</div><div>Line(21) = {9,12};</div><div><br></div><div><br></div><div>Line Loop(14) = {3,4,1,2};</div><div>Plane Surface(15) = {14};</div><div>Line Loop(16) = {6,7,8,9};</div><div>Plane Surface(17) = {16};</div><div>Line Loop(18) = {10,-9,-11,-4};</div><div>Plane Surface(19) = {18};</div><div>Line Loop(20) = {-8,11,-1,-13};</div><div>Plane Surface(21) = {20};</div><div>Line Loop(22) = {-12,-7,13,-2};</div><div>Plane Surface(23) = {22};</div><div>Line Loop(24) = {-6,12,-3,-10};</div><div>Plane Surface(25) = {24};</div><div><br></div><div>Surface Loop(1) = {17,-25,-23,-21,19,15};</div><div>Volume(1) = {1};</div><div><br></div><div>Line Loop(26) = {18,-15,8,14};</div><div>Line Loop(27) = {14,-21,-17,-9};</div><div>Line Loop(28) = {20,-17,6,16};</div><div>Line Loop(29) = {16,-19,-15,-7};</div><div>Line Loop(30) = {18,19,20,21};</div><div><br></div><div>Plane Surface(26)={26};</div><div>Plane Surface(27)={27};</div><div>Plane Surface(28)={28};</div><div>Plane Surface(29)={29};</div><div>Plane Surface(30)={30};</div><div><br></div><div>Surface Loop(2) = {-17,27,26,29,30,28};</div><div>Volume(2) = {2};</div><div><br></div><div>// transfinite volume 1</div><div>Transfinite Line{1,3,6,8} = nx;</div><div>Transfinite Line{2,4,7,9} = ny;</div><div>Transfinite Line{10,11,12,13} = nz;</div><div><br></div><div>Transfinite Surface {15} = {1,2,3,4};</div><div>Transfinite Surface {17} = {5,6,7,8};</div><div>Transfinite Surface {19} = {1,5,8,4};</div><div>Transfinite Surface {21} = {8,7,3,4};</div><div>Transfinite Surface {23} = {6,7,3,2};</div><div>Transfinite Surface {25} = {5,6,2,1};</div><div>Transfinite Volume{1} = {1,2,3,4,5,6,7,8};</div><div>Recombine Surface{15,19,17,21,23,25};</div><div><br></div><div>// transfinite volume 2</div><div>Transfinite Line{14,15,16,17} = 3;</div><div>Transfinite Line{18,19,20,21} = 5;</div><div><br></div><div>Transfinite Surface {27} = {5,9,12,8};</div><div>Transfinite Surface {26} = {12,11,7,8};</div><div>Transfinite Surface {29} = {10,11,7,6};</div><div>Transfinite Surface {30} = {9,10,11,12};</div><div>Transfinite Surface {28} = {9,10,6,5};</div><div>Transfinite Volume{2} = {5,6,7,8,9,10,11,12};</div><div><br></div><div>Mesh.Algorithm3D = 4; </div><div><br></div><div>The error is very strange:</div><div><font color="#ff0000">Incompatible surface 27 in transfinite volume 2</font></div><div><font color="#ff0000">Cannot use frontal 3D algorithm with quadrangles on boundary</font></div><div><font color="#ff0000"><br></font></div><div><font color="#000000">Did you encounter this kind of issue? Thank you.</font></div><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div>-------------------------------------------------</div><div>Feilin Jia, Research Assistant</div><div>Department of Aerospace Engineering</div><div>University of Kansas</div><div>Lawrence, Kansas, USA</div><div>-------------------------------------------------</div></div></div>
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