I would propose to think of the different schools of coming up with discretizations (FVM/FEM/FD), not as excluding or separate. There is surely overlap, they are -methods- to derive discretizations. As you said, in some cases you end up with
identical discretizations no matter which approach you chose. That being said,
there are certain advantages and ...
The difference between finite volumes and finite differences is really more about the form of the equations solved. In typical FV methods, the conservative form is discretised in terms of integrals and fluxes, whereas FD methods generally approximate derivatives in the non-conservative form directly.
Maintaining conservation and preserving physical ...
There are two different types of meshes that are commonly termed "structured":
the points are placed on an equispaced grid; and
the elements have the same connectivity.
Some people might call any combination of these two a "structured mesh".
In Abaqus, you can define a set of points on a grid with the keyword
and a regular connectivity with
If it's a structured grid of hexahedra, then each node should have the same valence (number of adjacent hexes), eight. So I would scan through the list of hexes, and make sure that each node index appears exactly eight times.
You can make structured grids from other types of elements, like by repeating a clump of tetrahedra over and over. In that case, ...