[Gmsh] [Bug?] Circular arc rotational extrusion and duplication

Stefan Tibus stefan.tibus at uni-konstanz.de
Fri Apr 3 09:51:56 CEST 2009


Hello,

the attached geometry file creates a spherical cap by drawing circular
arcs and rotational extrusion. However, upon duplicating the volume
(to the right) the geometry appears distorted.

I get the same distorted geometry when trying to create the cap not
by rotational extrusian, but drawing the appropriate boundary lines
and creating ruled surfaces. How can this distortion be avoided or
is it just a bug?

Question aside: For scripting purposes it seems hard to me to keep
track of the numbers of automatically created entities. Is there a
way to retrieve and store their numbers?

Thanks and regards,
Stefan
-------------- next part --------------
lctop = 5;
lcbottom = 3;

r = 50;
t = 10;
cx = 0;
cy = 0;
cz = 0;
d = 0.1;

Point(1) = {cx, cy, cz+r, lctop};
Point(2) = {cx, cy, cz, lcbottom};
Point(3) = {cx+r, cy, cz, lcbottom};

Point(4) = {cx+r, cy, cz+t, lcbottom};
Point(5) = {cx, cy, cz+t, lcbottom};
Point(6) = {cx, cy, cz+r+t, lctop};

Circle(1) = {1, 2, 3};
Line(2) = {3, 4};
Circle(3) = {4, 5, 6};

Extrude {{0, 0, 1}, {0, 0, 0}, Pi/2} {
  Line{1, 2, 3};
}
//       lower    outer      upper
// lines 4  5     7 xx  9    11 xx
// surf        6          10       13

Extrude {{0, 0, 1}, {0, 0, 0}, Pi/2} {
  Line{4, 7, 11};
}
//       lower    outer       upper
// lines 14 15    17 xx 19    21 xx
// surf        16          20       23

Extrude {{0, 0, 1}, {0, 0, 0}, Pi/2} {
  Line{14, 17, 21};
}
//       lower    outer       upper
// lines 24 25    27 xx 29    31 xx
// surf        26          30       33

Extrude {{0, 0, 1}, {0, 0, 0}, Pi/2} {
  Line{24, 27, 31};
}
//       lower    outer       upper
// lines 34 35    37 xx 39    41 xx
// surf        36          40       43

Surface Loop(44) = {36, 26, 16, 6, 10, 40, 30, 20, 23, 33, 43, 13};
Volume(45) = {44};
Physical Volume(46) = {45};

Translate {2*r+d, 0, 0} {
  Duplicata { Volume{45}; }
}