## Structured Grids - simpler to program → efficient solvers - neighbor connectivity - regular solver - can only be used for simple geometries ### H-Grid - Can be mapped into a rectangle ### O-Grid - One cooredinate line wraps around (endless) - Artificial cut where grid numbering jumps ### C-Grid ### Block-Structured Grids - Divide grid into subdivisions - ### Overlapping Grids - Also known as "composite" or "Chimera" grids ## Unstructured Grids Works for very complex geometries Only used for finite volume and finite element Triangles close to equilateral → midpoint rule works well - Easily refined (structured grids require renumbering the whole grid) - Aspect ratio is easily controlled - Can be made "orthogonal" Disadvanages: - nodes locations and neighbor connections need to be specified explicitly - Matrix to be solved is not regular, and the size of the band needs to be controlled by node ordering ### Advancing Front Method - Tetrahedras are built progressively inward from the boundary - Intersection checks ensure traignesl don't overlap #### Delaunay Triangulation Faster for 3D ## Velocity Vector Components ### Cartesian - Good for collocated arrangements ### Grid-Oriented - non-conservative terms appear - centrifugal and coriolis forces It's all just interpolation