New paper: High-order mesh generation with HOHQMesh
Our new paper "HOHQMesh: An All Quadrilateral/Hexahedral Unstructured Mesh Generator for High Order Element" has been published in the Journal of Open Source Software. We are happy we were able to contribute to the publication and thank all our collaborators for the great experience. HOHQMesh generates unstructured all-quadrilateral and hexahedral meshes with high order boundary information for use with spectral element solvers. Model input by the user requires only an optional outer boundary curve plus any number of inner boundary curves that are built as chains of simple geometric entities (lines and circles), user defined equations, and cubic splines. Inner boundary curves can be designated as interface boundaries to force element edges along them. Quadrilateral meshes are generated automatically with the mesh sizes guided by a background grid and the model, without additional input by the user. Hexahedral meshes are generated by extrusions of a quadrilateral mesh, including sweeping along a curve, and can follow bottom topography. The mesh files that HOHQMesh generates include high order polynomial interpolation points of arbitrary order.
Summary
Together with Erik Faulhaber, Sven Berger, Christian Weißenfels und Gregor Gassner, we have submitted our paper "Robust and efficient pre-processing techniques for particle-based methods including dynamic boundary generation".
Abstract
Obtaining high-quality particle distributions for stable and accurate particle-based simulations poses significant challenges, especially for complex geometries. We introduce a preprocessing technique for 2D and 3D geometries, optimized for smoothed particle hydrodynamics (SPH) and other particle-based methods. Our pipeline begins with the generation of a resolution-adaptive point cloud near the geometry's surface employing a face-based neighborhood search. This point cloud forms the basis for a signed distance field, enabling efficient, localized computations near surface regions. To create an initial particle configuration, we apply a hierarchical winding number method for fast and accurate inside-outside segmentation. Particle positions are then relaxed using an SPH-inspired scheme, which also serves to pack boundary particles. This ensures full kernel support and promotes isotropic distributions while preserving the geometry interface. By leveraging the meshless nature of particle-based methods, our approach does not require connectivity information and is thus straightforward to integrate into existing particle-based frameworks. It is robust to imperfect input geometries and memory-efficient without compromising performance. Moreover, our experiments demonstrate that with increasingly higher resolution, the resulting particle distribution converges to the exact geometry.