Title
On orienting edges of unstructured two- and three-dimensional meshes
Abstract
Finite element codes typically use data structures that represent unstructured meshes as collections of cells, faces, and edges, each of which require associated coordinate systems. One then needs to store how the coordinate system of each edge relates to that of neighboring cells. However, we can simplify data structures and algorithms if we can a priori orient coordinate systems in such a way that the coordinate systems on the edges follow uniquely from those on the cells by rule. Such rules require that every unstructured mesh allow the assignment of directions to edges that satisfy the convention in adjacent cells. We show that the convention chosen for unstructured quadrilateral meshes in the deal.II library always allows to orient meshes. It can therefore be used to make codes simpler, faster, and less bug prone. We present an algorithm that orients meshes in O(N) operations. We then show that consistent orientations are not always possible for 3D hexahedral meshes. Thus, cells generally need to store the direction of adjacent edges, but our approach also allows the characterization of cases where this is not necessary. The 3D extension of our algorithm either orients edges consistently, or aborts, both within O(N) steps.
Year
DOI
Venue
2017
10.1145/3061708
ACM Transactions on Mathematical Software (TOMS)
Keywords
DocType
Volume
Finite Element Meshes,Orienting Edges,Quadrilateral and Hexahedral Meshes,Mesh generation,finite element meshes,orientation of edges,quadrilateral and hexahedral meshes
Journal
44
Issue
ISSN
Citations 
1
0098-3500
3
PageRank 
References 
Authors
0.40
8
4
Name
Order
Citations
PageRank
rainer agelek130.40
Michael Anderson212519.21
W. Bangerth322216.92
William Barth4919.96