Gmsh
To demonstrate how NekMesh
works, we will define a simple channel-like 3D geometry. First,
we must define the Gmsh
geometry to be used. The Gmsh
definition is given below, and is
visualised in figure 4.1.
Whilst a full tutorial on Gmsh
is far beyond the scope of this document, note the use of the
Recombine
argument. This allows us to generate a structured hexahedral mesh; remove the
first Recombine
to generate a prismatic mesh and both occurances to generate a tetrahedral
mesh. Increasing the Layers
numbers refines the mesh in the radial and azimuthal direction
respectively.