Structured grids have a regular topology where the neighborhood
relation between all points is captured with a two- or three-dimensional
array. By incrementing or decrementing the array index the point neighbors
can be directly accessed. Historically, structured grid generation was a
first attempt to automate the meshing process for simple shapes.
Through mathematical transformations an ortho-product grid of the unit
square/cube is mapped onto the simulation domain. In literature it is often
referred to as *numerical grid generation*
[78,24,184,60].
*Multi block structured grid generation* combines several simple
blocks to form more complex shapes. Cutting the simulation domain into
these blocks is strictly speaking the same task as unstructured mesh
generation and poses the same difficulties.
The *Chimera* or *overlapping* approach allows overlapping
blocks. Each structured grid component can be generated independently from
the other parts. It must only be guaranteed that the blocks overlap
sufficiently to allow interpolation between the component grids.
A more detailed overview can be found in [61].
The two mathematically different mapping techniques are shortly summarized
in the next paragraphs.

2000-01-20