// 先定义几个特征长度：

lcar1 = .1;

lcar2 = .0005;

lcar3 = .075;

// 为了能够不修改文件，而全局的改变这些长度，我们能够在

// 命令行指定一个因子或者指定 Mesh.CharacteristicLengthFactor

// 选项来达成。例如

//

// $ gmsh t5 -clscale 1

//

// 将会产生一个大约两千个节点和一万个四面体的网格（在一台

// 666M 主频的 Alpha Workstation 上需要约 3 秒钟）。而

//

// $ gmsh t5 -clscale 0.2

//

// 会将所有的特征长度都缩小 5 倍，得到的网格将有大约 17 万

// 个节点，和大约 100 万个四面体，在同样的机器上，这需要花

// 费大约 16 分钟的时间，Gmsh 还需要很多改进来达到更高的效

// 率。

Point(1) = {0.5,0.5,0.5,lcar2}; Point(2) = {0.5,0.5,0,lcar1};

Point(3) = {0,0.5,0.5,lcar1};   Point(4) = {0,0,0.5,lcar1}; 

Point(5) = {0.5,0,0.5,lcar1};   Point(6) = {0.5,0,0,lcar1};

Point(7) = {0,0.5,0,lcar1};     Point(8) = {0,1,0,lcar1};

Point(9) = {1,1,0,lcar1};       Point(10) = {0,0,1,lcar1};

Point(11) = {0,1,1,lcar1};      Point(12) = {1,1,1,lcar1};

Point(13) = {1,0,1,lcar1};      Point(14) = {1,0,0,lcar1};

Line(1) = {8,9};    Line(2) = {9,12};  Line(3) = {12,11};

Line(4) = {11,8};   Line(5) = {9,14};  Line(6) = {14,13};

Line(7) = {13,12};  Line(8) = {11,10}; Line(9) = {10,13};

Line(10) = {10,4};  Line(11) = {4,5};  Line(12) = {5,6};

Line(13) = {6,2};   Line(14) = {2,1};  Line(15) = {1,3};

Line(16) = {3,7};   Line(17) = {7,2};  Line(18) = {3,4};

Line(19) = {5,1};   Line(20) = {7,8};  Line(21) = {6,14};

Line Loop(22) = {11,19,15,18};       Plane Surface(23) = {22};

Line Loop(24) = {16,17,14,15};       Plane Surface(25) = {24};

Line Loop(26) = {-17,20,1,5,-21,13}; Plane Surface(27) = {26};

Line Loop(28) = {4,1,2,3};           Plane Surface(29) = {28};

Line Loop(30) = {7,-2,5,6};          Plane Surface(31) = {30};

Line Loop(32) = {6,-9,10,11,12,21};  Plane Surface(33) = {32};

Line Loop(34) = {7,3,8,9};           Plane Surface(35) = {34};

Line Loop(36) = {10,-18,16,20,-4,8}; Plane Surface(37) = {36};

Line Loop(38) = {-14,-13,-12,19};    Plane Surface(39) = {38};

// 除了使用文件包含机制以外，我们还能定义函数。在下面的函数中，

// 我们使用了保留词 'newp'，这样能够自动的选择一个新的点数。这

// 个数是当前最大数加一得到的。相似的，'newreg' 保留词是所有除

// 去点以外的实体数中最大的加一。

//

// 这里还没有局部变量，在将来的版本中，我们会加入相应的功能。

Function CheeseHole 

  p1 = newp; Point(p1) = {x,  y,  z,  lcar3} ;

  p2 = newp; Point(p2) = {x+r,y,  z,  lcar3} ;

  p3 = newp; Point(p3) = {x,  y+r,z,  lcar3} ;

  p4 = newp; Point(p4) = {x,  y,  z+r,lcar3} ;

  p5 = newp; Point(p5) = {x-r,y,  z,  lcar3} ;

  p6 = newp; Point(p6) = {x,  y-r,z,  lcar3} ;

  p7 = newp; Point(p7) = {x,  y,  z-r,lcar3} ;

  c1 = newreg; Circle(c1) = {p2,p1,p7};

  c2 = newreg; Circle(c2) = {p7,p1,p5};

  c3 = newreg; Circle(c3) = {p5,p1,p4};

  c4 = newreg; Circle(c4) = {p4,p1,p2};

  c5 = newreg; Circle(c5) = {p2,p1,p3};

  c6 = newreg; Circle(c6) = {p3,p1,p5};

  c7 = newreg; Circle(c7) = {p5,p1,p6};

  c8 = newreg; Circle(c8) = {p6,p1,p2};

  c9 = newreg; Circle(c9) = {p7,p1,p3};

  c10 = newreg; Circle(c10) = {p3,p1,p4};

  c11 = newreg; Circle(c11) = {p4,p1,p6};

  c12 = newreg; Circle(c12) = {p6,p1,p7};

// 下面我们定义了一些约束曲面：

  l1 = newreg; Line Loop(l1) = {c5,c10,c4};   Ruled Surface(newreg) = {l1};

  l2 = newreg; Line Loop(l2) = {c9,-c5,c1};   Ruled Surface(newreg) = {l2};

  l3 = newreg; Line Loop(l3) = {-c12,c8,c1};  Ruled Surface(newreg) = {l3};

  l4 = newreg; Line Loop(l4) = {c8,-c4,c11};  Ruled Surface(newreg) = {l4};

  l5 = newreg; Line Loop(l5) = {-c10,c6,c3};  Ruled Surface(newreg) = {l5};

  l6 = newreg; Line Loop(l6) = {-c11,-c3,c7}; Ruled Surface(newreg) = {l6};

  l7 = newreg; Line Loop(l7) = {c2,c7,c12};   Ruled Surface(newreg) = {l7};

  l8 = newreg; Line Loop(l8) = {-c6,-c9,c2};  Ruled Surface(newreg) = {l8};

// 曲面上的网格是通过将二维的网格投影到曲面的平均曲面上得到

// 的，这样只有当曲率很小的时候才能够得到比较好的效果，否则

// 的话，您需要将曲面手工分成很小的小片。

// 变量数组能够和变量一样进行操作。注意：对于一个没有初始化

// 的变量的读写会产生不可预知的结果。数组中的所有元素能够同

// 时初始化，如 l[]={1,2,7}。

  theloops[t] = newreg ; 

  Surface Loop(theloops[t]) = {l8+1, l5+1, l1+1, l2+1, -(l3+1), -(l7+1), l6+1, l4+1};

  thehole = newreg ; 

  Volume(thehole) = theloops[t] ;

Return

x = 0 ; y = 0.75 ; z = 0 ; r = 0.09 ;

// 这里使用一个 For 循环来产生立方体中的五个洞：

For t In {1:5}

  x += 0.166 ; 

  z += 0.166 ; 

// 调用函数






收藏
分享邀请

举报