This is probably an advanced example and useless for a beginner user. However, it shows some interesting GiD features.
Let's suppose that the previously studied horn is intended to illuminate a reflector. This reflector is provided by a third party mesher. But the mesh is to fine for a computation with a reasonable CPU time. GiD enables the user to import a mesh as a geometry surface :
Files => Import => Surface Mesh. The mesh is converted into a surface. This is not a real NURBS surface and doesn't support most of the surface operations. However, a powerful support is the possibility to re mesh this surface independently form the original mesh.
Re open the rectangular horn with a waveguide source and save it with another name. The reflector will be in an offset position. Because of that, there is only one symmetry plane left. Keep one half of the geometry (the cut plane is OZY).
Import the reflector stored in halfReflector.msh :
The imported surface is not located at the required position. Move it with the following instructions :
Rotate 45° around the Z axis
Rotate 90° around the Y axis
Translate 12.8 m toward the Z axis
The final geometry :
Because of the polarization of the source, the remaining symmetry plane is the E symmetry.
Remove the near field output (optional).
Request a finer far field output (optional, but recommended since the radiation pattern is expected to be sharp) :
Before creating the mesh, use the Mesh=>Unstructured=>Assign sizes on surfaces GiD menu to assign a mesh size of 0.1 (a third of the wavelength at 1GHz). This may be a very coarse mesh, but since the surface is a reflector, the currents are supposed to vary slowly.
Mesh the structure with the default size. The obtained mesh clearly shows the different mesh quality :
Save and launch the computation.
The computed far field pattern :
The previous 3D far field pattern clearly shows the advantage of a 3D view included in the geometry. For example, it is very easy to check if the radiation peak is in the expected direction. But for more precise display, the curves visualization is a better choice :
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