Robust and efficient cartesian mesh generation for component-based geometry

This work documents a new method for rapid and robust Cartesian mesh generation for componentbased geometry. The new algorithm adopts a novel strategy which first intersects the components to extract the wetted surface before proceeding with volume mesh generation in a second phase. The intersection scheme is based on a robust geometry engine that uses adaptive precision arithmetic and which automatically and consistently handles geometric degeneracies with an algorithmic tie-breaTdng routine. The intersection procedure has worse case computational complexity of O(N logN) and is demonstrated on test cases with up to 121 overlapping and intersecting components including a variety of geometric degeneracies. The volume mesh generation takes the intersected surface triangulatipn as input and generates the mesh through cell division of an initially uniform coarse grid. In refining hexagonal cells to resolve the geometry, the new approach preserves the ability to directionally divide cells which are well-aligned with local geometry. The mesh generation scheme has linear asymptotic complexity with memory requirements that total approximately 14 words/cell. The mesh generation speed is approximately 10⁶ cells/minute on a 195Mhz RISC R10000 workstation.