Automatic scheme selection for toolkit hex meshing

International Journal for Numerical Methods in Engineering, John Wiley, Vol 49, Num 1, pp.127-144, September 10-20 2000

MESHING
RESEARCH
CORNER

Special Edition on Unstructured Mesh Generation
International Journal for Numerical Methods in Engineering, Vol 49 Number 1-2, 10-20 September 2000

Correspondence to: Timothy J. Tautges, 1500 Johnson Drive, Madison, WI 53706, U.S.A.
E-mail: drwhite@sandia.gov
E-mail: tjtautg@sandia.gov

Abstract
Current hexahedral mesh generation techniques rely on a set of meshing tools, which when combined with geometry decomposition leads to an adequate mesh generation process. Of these tools, sweeping tends to be the workhorse algorithm, accounting for at least 50 per cent of most meshing applications. Constraints which must be met for a volume to be sweepable are derived, and it is proven that these constraints are necessary but not sufficient conditions for sweepability. This paper also describes a new algorithm for detecting extruded or sweepable geometries. This algorithm, based on these constraints, uses topological and local geometric information, and is more robust than feature recognition-based algorithms. A method for computing sweep dependencies in volume assemblies is also given. The auto sweep detect and sweep grouping algorithms have been used to reduce interactive user time required to generate all-hexahedral meshes by filtering out non-sweepable volumes needing further decomposition and by allowing concurrent meshing of independent sweep groups. Parts of the auto sweep detect algorithm have also been used to identify independent sweep paths, for use in volume-based interval assignment.