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};