-- FreeFem++ v4.14 (mer. 06 mars 2024 16:59:04 CET - git v4.14-1-g2b2052ae)
   file : mesh_construction.edp
 Load: lg_fem lg_mesh lg_mesh3 eigenvalue 
    1 : //  mesh_construction.edp
    2 : //
    3 : //  Discussion:
    4 : //
    5 : //    Construct a mesh for a contraction flow problem.
    6 : //
    7 : //  Licensing:
    8 : //
    9 : //    This code is distributed under the MIT license.
   10 : //
   11 : //  Modified:
   12 : //
   13 : //    25 May 2020
   14 : //
   15 : //  Reference:
   16 : //
   17 : //    John Chrispell, Jason Howell,
   18 : //    Finite Element Approximation of Partial Differential Equations
   19 : //    Using FreeFem++, or, How I Learned to Stop Worrying and Love
   20 : //    Numerical Analysis.
   21 : //
   22 : //    Frederic Hecht,
   23 : //    New development in FreeFem++,
   24 : //    Journal of Numerical Mathematics,
   25 : //    Volume 20, Number 3-4, 2012, pages 251-265.
   26 : //
   27 : cout << "\n";
   28 : cout << "mesh_construction():\n";
   29 : cout << "  FreeFem++ version\n";
   30 : cout << "  Demonstrate how to define a region with line se
  ... : gments,\n";
   31 : cout << "  and then mesh it.\n";
   32 : //
   33 : //  Use N to control the relative fineness of the mesh.
   34 : //  N = 1 will be the coarsest possible mesh.
   35 : //
   36 : int n = 3;
   37 : //
   38 : //  Define line segments that form the boundary.
   39 : //  We break up each line so that we can force parts to have a finer mesh.
   40 : //
   41 : // Bottom edge.
   42 : //
   43 : border l00 ( t = 0, 1 ) { x = 0.0 + 2.0 * t; y = 0.0;               label = 1; }; 
   44 : border l01 ( t = 0, 1 ) { x = 2.0 + 1.5 * t; y = 0.0;               label = 1; };
   45 : border l02 ( t = 0, 1 ) { x = 3.5 + 1.0 * t; y = 0.0;               label = 1; };
   46 : border l03 ( t = 0, 1 ) { x = 4.5 + 3.5 * t; y = 0.0;               label = 1; };
   47 : //
   48 : // Outflow edge
   49 : //
   50 : border l04 ( t = 0, 1 ) { x = 8.0;           y = 0.0   + 0.125 * t; label = 2; };
   51 : border l05 ( t = 0, 1 ) { x = 8.0;           y = 0.125 + 0.125 * t; label = 2; };
   52 : //
   53 : // Top of contraction channel
   54 : //
   55 : border l06 ( t = 0, 1 ) { x = 8.0 - 3.5 * t; y = 0.250;             label = 3; }; 
   56 : border l07 ( t = 0, 1 ) { x = 4.5 - 0.5 * t; y = 0.250;             label = 3; };
   57 : //
   58 : // Contraction wall
   59 : //
   60 : border l08 ( t = 0, 1 ) { x = 4.0;           y = 0.250 + 0.125 * t; label = 4; }; 
   61 : border l09 ( t = 0, 1 ) { x = 4.0;           y = 0.375 + 0.250 * t; label = 4; };
   62 : border l10 ( t = 0, 1 ) { x = 4.0;           y = 0.625 + 0.375 * t; label = 4; };
   63 : //
   64 : // Top of inflow channel
   65 : //
   66 : border l11 ( t = 0, 1 ) { x = 4.0 - 0.5 * t; y = 1.0;               label = 5; }; 
   67 : border l12 ( t = 0, 1 ) { x = 3.5 - 1.5 * t; y = 1.0;               label = 5; };
   68 : border l13 ( t = 0, 1 ) { x = 2.0 - 2.0 * t; y = 1.0;               label = 5; };
   69 : //
   70 : // Inflow walls.
   71 : //
   72 : border l14 ( t = 0, 1 ) { x = 0.0;           y = 1.000 - 0.375 * t; label = 6; };
   73 : border l15 ( t = 0, 1 ) { x = 0.0;           y = 0.625 - 0.250 * t; label = 6; };
   74 : border l16 ( t = 0, 1 ) { x = 0.0;           y = 0.375 - 0.250 * t; label = 6; };
   75 : border l17 ( t = 0, 1 ) { x = 0.0;           y = 0.125 - 0.125 * t; label = 6; };
   76 : //
   77 : //  Build the mesh.
   78 : //  We particularly want a fine mesh near the transition region at x = 4.0.
   79 : //
   80 : mesh Th = buildmesh 
   81 : (
   82 :     l00 ( 4 * n ) // Bottom edge
   83 :   + l01 ( 4 * n )
   84 :   + l02 ( 8 * n )
   85 :   + l03 ( 10 * n )
   86 :   + l04 ( 4 * n ) // Outflow edge
   87 :   + l05 ( 4 * n )
   88 :   + l06 ( 10 * n ) // Top of contraction channel
   89 :   + l07 ( 4 * n )
   90 :   + l08 ( 4 * n ) // Contraction wall
   91 :   + l09 ( 4 * n ) 
   92 :   + l10 ( 4 * n )
   93 :   + l11 ( 4 * n ) // Top of inflow channel
   94 :   + l12 ( 4 * n )
   95 :   + l13 ( 4 * n )
   96 :   + l14 ( 4 * n ) // Inflow walls.
   97 :   + l15 ( 4 * n )
   98 :   + l16 ( 8 * n )
   99 :   + l17 ( 2 * n )
  100 : );
  101 : //
  102 : //  Display the mesh.
  103 : //
  104 : plot ( Th, wait = true, ps = "mesh_construction.ps" );
  105 : //
  106 : //  Terminate.
  107 : //
  108 : cout << "\n";
  109 : cout << "mesh_construction():\n";
  110 : cout << "  Normal end of execution.\n";
  111 : 
  112 : exit ( 0 );
  113 :  sizestack + 1024 =1552  ( 528 )


mesh_construction():
  FreeFem++ version
  Demonstrate how to define a region with line segments,
  and then mesh it.
  --  mesh:  Nb of Triangles =   1776, Nb of Vertices 1024

mesh_construction():
  Normal end of execution.
  current line = 112
exit(0)
 err code 0 ,  mpirank 0
 CodeAlloc : nb ptr  4370,  size :538800 mpirank: 0
Ok: Normal End