On 22 Mar 2013, at 11:33, Dorin Niculescu <[email protected]> wrote:
> Hello Filipe, > > Thank you for your quick answer. Yes, i've tried to use Periodic Surface too > but the result is even worst, the mesh seems to be the same on all the faces > but when you are testing the coordinates you can see that there is a > difference (not really big, but it can introduce errors in the solution). To > find the corresponding mesh points i had to code a subroutine for testing > numbers which allows me to set a tolerance. When i use Extrude and > Transfinite Surface i find perfectly corresponding mesh just on the first > direction in which i extrude (i've tried to extrude in the other two > directions hoping that it will work, but with no result). Is this a bug (i'm > using Gmsh v 2.5.1) or is like this that it is supposed to work? > The periodic surface code has been rewritten in version 2.7: can you give it a try? > Thank you very much for your time! > > Dorin > > From: F. A. Portela <[email protected]> > To: Dorin Niculescu <[email protected]> > Cc: "[email protected]" <[email protected]> > Sent: Thursday, 21 March 2013, 23:34 > Subject: Re: [Gmsh] 3D Periodic Boundary Conditions > > Hi Dorin, > > You can add this lines at the end of your .geo to force the opposing faces to > have the same mesh: > > Periodic Surface 27 {4,13,11,22} = 19 {-2,14,-9,18}; > Periodic Surface 6 {2,3,4,1} = 28 {9,10,11,8}; > Periodic Surface 15 {14,8,13,1} = 23 {18,-10,22,-3}; > > However it seems to me that by making the faces transfinite you should not > require this... > > Cheers, > Felipe > > > -- > Felipe Alves Portela > MSc student in Aerospace Eng. at TU Delft > http://www.linkedin.com/in/felipealvesportela > > > On 21 March 2013 11:28, Dorin Niculescu <[email protected]> wrote: > Hello all, > > I am trying to implement periodic boundary conditions for my 3D CFD code and > i have troubles generating matching points on the opposite faces of a simple > cube. I've used Extrude and Transfinite Surface as you can see below but the > points seems to match perfectly only for the zy plan. Is there a way to make > them match on the other two plans too? > > cl = 20.0; > Point(1) = {-50, 50, 50, cl}; > Point(2) = {-50, -50, 50, cl}; > Point(3) = {-50, -50, -50, cl}; > Point(4) = {-50, 50, -50, cl}; > Line(1) = {1, 2}; > Line(2) = {2, 3}; > Line(3) = {3, 4}; > Line(4) = {4, 1}; > Line Loop(5) = {1, 2, 3, 4}; > Plane Surface(6) = {5}; > Extrude {100, 0, 0} { > Surface{6}; > } > Extrude {0, 0, -100} { > Surface{15}; > } > Extrude {0, 100, 0} { > Surface{19}; > } > Transfinite Surface {6} = {1, 2, 3, 4}; > Transfinite Surface {28} = {5, 6, 10, 14}; > Transfinite Surface {15} = {1, 2, 6, 5}; > Transfinite Surface {23} = {4, 3, 10, 14}; > Transfinite Surface {19} = {2, 6, 10, 3}; > Transfinite Surface {27} = {1, 5, 14, 4}; > > > Thank you verry much for your time. > > Dorin Niculescu > > _______________________________________________ > gmsh mailing list > [email protected] > http://www.geuz.org/mailman/listinfo/gmsh > > > > > _______________________________________________ > gmsh mailing list > [email protected] > http://www.geuz.org/mailman/listinfo/gmsh -- Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine _______________________________________________ gmsh mailing list [email protected] http://www.geuz.org/mailman/listinfo/gmsh
