Transparent and fixed boundariesΒΆ

Learning targets

  • Specify fixed boundary conditions for a 3D computational domain

  • Non-rectangular computational domains

This geometry example specifies a rectangular computational domain with fixed boundary identifiers on the y==0 and x==0 planes and with transparent boundaries elsewhere. This is a typical situation for light scattering simulations with periodic, mirror-symmetrical scattering objects where the size of the computational domain can be reduced by a factor of 4 when symmetry considerations about the geometry and the source (e.g., plane wave at perpendicular incidence) are taken into account. Please compare examples 3D Periodic boundaries I and 2D Transparent and fixed boundaries. The resulting geometry and mesh in different views correspond to the following figure:

_images/figure_360.png

.jcm Input File

  • layout.jcm [ASCII]

     1Layout3D {
 2  Name = "TutorialExample3D"
 3  UnitOfLength = 1e-6
 4  MeshOptions {    
 5    MinimumMeshAngle = 20
 6    MaximumSideLength = 0.75
 7  }
 8  Extrusion {
 9    Objects {
10      Polygon { 
11        Name = "ComputationalDomain/Background" 
12        DomainId = 101 
13        Priority = -1 
14        Points = [0 0, 2 0, 2 2, 0 2] 
15        Boundary { 
16          Number = 1 
17          Class = Domain
18          BoundaryId = 1
19        } 
20        Boundary { 
21          Number = [ 2 3]
22          Class = Transparent
23        }         
24        Boundary { 
25          Number = 4
26          Class = Domain
27          BoundaryId = 2
28        } 
29      } 
30      Polygon {  
31        Name = "Diamond_for_extrusion"  
32        DomainId = 102 
33        Priority = 1 
34        Points = [0 -1.5, 1.2 0, 0 1.5, -1.2 0]
35      } 
36      Circle {
37        Name = "Circle_for_extrusion"
38        DomainId = 103
39        Priority = 2
40        Radius = 0.5
41        RefineAll = 1
42        MeshOptions{
43          MaximumSideLength = 0.4
44        }
45      }
46    }
47    MultiLayer {
48      LayerInterface {
49        BoundaryClass = Transparent
50      }
51      Layer {
52        Thickness = 0.5
53        DomainId = 1
54      }
55      Layer {
56        Thickness = 0.75
57        DomainIdMapping = [101 2, 102 3, 103 3]
58      }
59      Layer {
60        Thickness = 0.4
61        DomainIdMapping = [101 2, 102 2, 103 4]
62      }
63      Layer {
64        Thickness = 0.4
65        DomainIdMapping = [101 2, 102 2, 103 2]
66      }
67      LayerInterface {
68        BoundaryClass = Transparent
69      }
70    }  
71  }
72}