円孔1/4対称、四角形メッシュ

トンネルのようなモデル
赤はGUIで操作した部分
emacsで編集、GUIで編集を繰り返して作成

l = 2 ;

Point(10) = {0, 0, 0, l};
Point(20) = {1, 0, 0, l} ;
Point(30) = {0, 1, 0, l} ;
Point(40) = {2, 0, 0, l} ;
Point(50) = {0, 2, 0, l} ;
Point(60) = {Sin(Pi/4),Sin(Pi/4),0,l} ;
Point(70) = {2*Sin(Pi/4),2*Sin(Pi/4),0,l} ;
Point(100)={3, 0, 0, l} ;
Point(110)={3, 3, 0, l} ;
Point(120)={0, 3, 0, l} ;


Circle(1) = {20,10,60};
Circle(2) = {60,10,30};
Circle(3) = {40,10,70};
Circle(4) = {70,10,50};
Line(5) = {20,40};
Line(6) = {40,100};
Line(7) = {100,110};
Line(8) = {110,120};
Line(9) = {120,50};
Line(10) = {50,30};
Line(11) = {60,70};
Line(12) = {70,110};

Transfinite Line{1,3,2,4,8,7}=5+1;
Transfinite Line{5,11,10}=2+1;
Transfinite Line{6,12,9}=4+1;

Line Loop(13) = {1,11,-3,-5};
Plane Surface(14) = {13};
Transfinite Surface{14}={20,40,70,60};
Recombine Surface{14};

Line Loop(15) = {2,-10,-4,-11};
Plane Surface(16) = {15};
Transfinite Surface{16}={60,70,50,30};
Recombine Surface{16};

Line Loop(17) = {12,8,9,-4};
Plane Surface(18) = {17};
Transfinite Surface{18}={70,50,120,110};
Recombine Surface{18};

Line Loop(19) = {7,-12,-3,6};
Plane Surface(20) = {19};
Transfinite Surface{20}={40,100,110,70};
Recombine Surface{20};

Physical Surface(21) = {20,14,16,18};

バームクーヘンを四角形要素で

l = 2 ;

Point(1) = {0, 0, 0, l};
Point(2) = {1, 0, 0, l} ;
Point(3) = {0, 1, 0, l} ;
Point(4) = {2, 0, 0, l} ;
Point(5) = {0, 2, 0, l} ;

Circle(1001)={2,1,3};
Circle(1002)={5,1,4};
Line(1003)={4,2};
Line(1004)={3,5};

Line Loop(1101)={1001,1004,1002,1003};
Plane Surface(2001)={1101};

Transfinite Line{1001,1002}=11;
Transfinite Line{1003,1004}=3;
Transfinite Surface{2001}={2,3,5,4};
Recombine Surface {2001};

MySurface = 100;
Physical Surface(MySurface) = {3001} ;

正方形を四角形要素で分割

l = 2 ;

Point(1) = {0, 0, 0, l};
Point(2) = {1, 0, 0, l} ;
Point(3) = {1, 1, 0, l} ;
Point(4) = {0, 1, 0, l} ;

Line(11) = {1,2} ;
Line(12) = {2,3} ;
Line(13) = {3,4} ;
Line(14) = {4,1} ;

Line Loop(5) = {11,12,13,14} ;

Plane Surface(6) = {-5} ;
Transfinite Line{11,12,13,14}=10;
Transfinite Surface{6}={1,2,3,4};
Recombine Surface {6};

// Consequently, two punctual elements will be saved in the output
// files, both with the region number 1. The mechanism is identical
// for line or surface elements:

// Physical Line(10) = {1,2,4} ;

MySurface = 100;
Physical Surface(MySurface) = {6} ;