Efficient Symmetry-Based Decomposition for Meshing Quasi-Axisymmetric Assemblies

This paper describes a decomposition strategy for hex meshing CAD assembly models consisting of quasi-axisymmetric components. A symmetry-based decomposition technique is used to isolate portions of model boundaries based upon their cyclic symmetry attributes. The calculation of assembly interfaces enables symmetry attributes to be passed between adjacent components with the overall ambition of achieving a decomposition suitable for conformal hex mesh generation of assemblies with quasi-axisymmetric components. The decomposition facilitates a multi-sweep approach to hex meshing where axisymmetric and transition portions of the boundary are sweepable in the circumferential and radial directions respectively. The symmetry-based decomposition is reduced to its equivalent meshable representation where axisymmetric regions are represented by their 2D profile, reflective symmetry is exploited for transition regions and cyclic symmetric regions are defined by a master cyclic segment and a series of transformations. This equivalent meshable representation massively reduces the meshing burden for hex mesh generation.