[Gmsh] Extrusion produces an incorrect number of layers
Felix Salazar
felix.salazar at polymtl.ca
Wed Nov 6 01:06:42 CET 2013
After each extrusion:
Delete one;
Delete layer;
That did the trick
Thanks, and sorry for the spamming. I was stuck with this issue, but manage
to solve after I wrote to the mailing list. Thanks again,
------------------------------------
*Félix Salazar**felix.salazar at polymtl.ca <felix.salazar at polymtl.ca>*
Étudiant au doctorat - PhD Student
*École Polytechnique de Montréal*
* LADYF*
Lab. de dynamique des fluides
(514) 340 4711 ext 2489
Local: C-318.21.3
------------------------------------
On Tue, Nov 5, 2013 at 7:00 PM, Felix Salazar <felix.salazar at polymtl.ca>wrote:
> I found the problem. I should restart the internal variables one[] and
> layer[] after each extrusion. How do I do that in Gmsh?
>
> ------------------------------------
>
> * Félix Salazar**felix.salazar at polymtl.ca <felix.salazar at polymtl.ca>*
> Étudiant au doctorat - PhD Student
> *École Polytechnique de Montréal*
> * LADYF*
> Lab. de dynamique des fluides
> (514) 340 4711 ext 2489
> Local: C-318.21.3
> ------------------------------------
>
>
> On Tue, Nov 5, 2013 at 6:48 PM, Felix Salazar <felix.salazar at polymtl.ca>wrote:
>
>> In my previous message, I said 8 layers in the 1st and 3rd extrusion, but
>> they are actually 10. The rest it's still valid
>>
>> ------------------------------------
>>
>> * Félix Salazar**felix.salazar at polymtl.ca <felix.salazar at polymtl.ca>*
>> Étudiant au doctorat - PhD Student
>> *École Polytechnique de Montréal*
>> * LADYF*
>> Lab. de dynamique des fluides
>> (514) 340 4711 ext 2489
>> Local: C-318.21.3
>> ------------------------------------
>>
>>
>> On Tue, Nov 5, 2013 at 6:17 PM, Felix Salazar <felix.salazar at polymtl.ca>wrote:
>>
>>> I'm building a cylindrical geometry using extrusion, and managed to put
>>> a Bump like layer distribution, using a modified version of an example
>>> given by Christophe in the mailing list. (It's actually a double
>>> progression). The script is not clean, and probably not very efficient, but
>>> it works. Or at least, it seems to work.
>>>
>>> Part of my geometry includes a simple extrusion of a circle 3 times,
>>> with different length and layer distribution. The 1st and 3rd section
>>> should be identical. However, Gmsh is giving at least an additional layer
>>> in the 3rd section, with the normal in the opposite direction of the rest
>>> of extrusion.
>>>
>>> Here's the simplified script reproducing the problem. I tested it in
>>> Gmsh 2.8, 2.6 and 2.5, with the same result.
>>>
>>> //==== BEGIN OF .GEO
>>> /*==============================*/
>>> /*==== Geometric parameters ====*/
>>> /*==============================*/
>>> D1 = 1;
>>> D2 = 1.00;
>>> L = D1;
>>> BL = 0.5;
>>> //==============================
>>> factorRefinement = 1.0;
>>> core = 4;
>>> radial = Ceil((R1+R2/4)/(BL/core));
>>> Rprog = 0.9;
>>> lc = R1*(Pi/2)/core;
>>> z1 = Ceil(factorRefinement*(L)/lc);
>>> z2 = Ceil(factorRefinement*(L/2)/lc);
>>> Zbump = 1.35;
>>> Geometry.ExtrudeReturnLateralEntities = 0;
>>> //==============================
>>> // LIST OF POINTS
>>> Point(1) = {0, 0, 0};
>>> Point(2) = {0, R1, 0};
>>> Point(3) = {0, BL*R1, 0};
>>>
>>> rot1[] = Rotate { {0,0,1}, {0,0,0}, Pi/2} {
>>> Duplicata{Point{2,3};}
>>> };
>>> rot2[] = Rotate { {0,0,1}, {0,0,0}, Pi/2} {
>>> Duplicata{Point{rot1[0],rot1[1]};}
>>> };
>>> rot3[] = Rotate { {0,0,1}, {0,0,0}, Pi/2} {
>>> Duplicata{Point{rot2[0],rot2[1]};}
>>> };
>>>
>>> Circle(1) = {2, 1, rot1[0]};
>>> Circle(2) = {rot1[0],1,rot2[0]};
>>> Circle(3) = {rot2[0],1,rot3[0]};
>>> Circle(4) = {rot3[0],1,2};
>>> Line(5) = {3, rot1[1]};
>>> Line(6) = {rot1[1],rot2[1]};
>>> Line(7) = {rot2[1],rot3[1]};
>>> Line(8) = {rot3[1],3};
>>> Transfinite Line {1,2,3,4,5,6,7,8} = Ceil(factorRefinement*core+1);
>>> Line(9) = {3,2};
>>> Line(10) = {rot1[1],rot1[0]};
>>> Line(11) = {rot2[1],rot2[0]};
>>> Line(12) = {rot3[1],rot3[0]};
>>> Transfinite Line {9,10,11,12} = Ceil(factorRefinement*radial+1) Using
>>> Progression Rprog;
>>>
>>> Line Loop(5) = {5,6,7,8};
>>> Plane Surface(5) = {-5};
>>> Line Loop(1) = {1,-10,-5,9};
>>> Plane Surface(1) = {-1};
>>> Line Loop(2) = {2,-11,-6,10};
>>> Plane Surface(2) = {-2};
>>> Line Loop(3) = {3,-12,-7,11};
>>> Plane Surface(3) = {-3};
>>> Line Loop(4) = {4,-9,-8,12};
>>> Plane Surface(4) = {-4};
>>> Transfinite Surface {5,1,2,3,4};
>>>
>>> //======================
>>> Function BumpExtrude
>>> n0 = Ceil(n/2);
>>> nN = n - n0;
>>> a0= (n0/n)*(r - 1) / ((r^n0) - 1);
>>> aN= (nN/n)*((1/r) - 1) / (((1/r)^nN) - 1);
>>>
>>> one[0] = 1;
>>> layer[0] = a0;
>>> Printf("%g %g",0,layer[0]);
>>> For i In {1:n-1}
>>> one[i] = 1;
>>> layer[i] = layer[i-1] + a0 * r^i;
>>> If(i>=n0)
>>> layer[i] = layer[i-1] + aN * (1/r)^(i-n0);
>>> EndIf
>>> Printf("%g %g",i,layer[i]);
>>> EndFor
>>> Return
>>> //======================
>>> n = 3*(z2+1) - 1; // number of intervals
>>> r = Zbump; // Bump progression
>>> Call BumpExtrude;
>>> Extrude {0,0,-L/2} {
>>> Surface{1,2,3,4,5}; Layers{one[], layer[]}; Recombine;
>>> }
>>> //======================
>>> n = 3*(z1+1) - 1; // number of intervals
>>> r = Zbump; // Bump progression
>>> Call BumpExtrude;
>>> Extrude {0,0,-L} {
>>> Surface{-34,-56,-78,-100,-122}; Layers{one[], layer[]}; Recombine;
>>> }
>>> //======================
>>> n = 3*(z2+1) - 1; // number of intervals
>>> r = Zbump; // Bump progression
>>> Call BumpExtrude;
>>> Extrude {0,0,-L/2} {
>>> Surface{-144,-166,-188,-210,-232}; Layers{one[], layer[]}; Recombine;
>>> }
>>> //=====OPTIONS=====
>>> Geometry.AutoCoherence = 1;
>>> Geometry.CopyMeshingMethod = 1;
>>> Geometry.LightTwoSide = 0;
>>> Geometry.Lines = 1;
>>> Geometry.LineNumbers = 1;
>>> Geometry.Points = 0;
>>> Geometry.PointNumbers = 0;
>>> Geometry.Surfaces = 1;
>>> Geometry.SurfaceNumbers = 1;
>>> Geometry.Volumes = 0;
>>> Mesh.Algorithm = 6;
>>> Mesh.Algorithm3D = 4;
>>> Mesh.CharacteristicLengthExtendFromBoundary = 0;
>>> Mesh.CharacteristicLengthFromCurvature = 0;
>>> Mesh.CharacteristicLengthFromPoints = 0;
>>> Mesh.ColorCarousel = 2;
>>> Mesh.LabelType = 2;
>>> Mesh.ElementOrder = 2;
>>> Mesh.Light = 0;
>>> Mesh.LightTwoSide = 0;
>>> Mesh.Lines = 0;
>>> Mesh.Optimize = 0;
>>> Mesh.RandomFactor = 1e-6;
>>> Mesh.ReverseAllNormals = 1;
>>> Mesh.SaveElementTagType = 2;
>>> Mesh.Format = 30;
>>> Mesh.SecondOrderIncomplete = 0;
>>> Mesh.SecondOrderLinear = 0;
>>> Mesh.Smoothing = 0;
>>> Mesh.SurfaceFaces = 1;
>>> Mesh.VolumeEdges = 0;
>>> Mesh.RecombineAll = 1;
>>> Mesh.Color.Zero = {177,149,255};
>>> Mesh.Color.One = {255,6,0};
>>> Mesh.Color.Two = {0,255,71};
>>> Mesh.Color.Three = {0,54,255};
>>> Mesh.Color.Four = {255,155,0};
>>> Mesh.Color.Six = {0,255,184};
>>> Mesh.Color.Seven = {195,255,152};
>>> Mesh.Color.Eight = {255,35,247};
>>> //END OF .GEO
>>>
>>> Note that the parameters for the first and 3rd extrusions are identical,
>>> with the exception of the surface list.
>>>
>>> I added a couple of lines, to print into console the position of the
>>> layers. The 1st and 3rd layer, with the parameters of the example, have 8
>>> layers according to the printed info, but the mesh on the screen shows
>>> something different.
>>>
>>> I tried tweaking some of the meshing options, without success.
>>> Displaying the normals show that the extra layer is somewhat "inverted" if
>>> compared with the others.
>>>
>>> Is there anything wrong with my Mesh options? Or the script has an error
>>> that I can't see. Any help is appreciated.
>>>
>>> Thanks,
>>>
>>> ------------------------------------
>>>
>>> * Félix Salazar**felix.salazar at polymtl.ca <felix.salazar at polymtl.ca>*
>>> Étudiant au doctorat - PhD Student
>>> *École Polytechnique de Montréal*
>>> * LADYF*
>>> Lab. de dynamique des fluides
>>> (514) 340 4711 ext 2489
>>> Local: C-318.21.3
>>> ------------------------------------
>>>
>>
>>
>
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