title: Unstructured hexahedral mesh generation of complex vascular trees using a multi-block grid-based approach.
abstract: The trend towards realistic numerical models of (pathologic) patient-specific vascular structures brings along larger computational domains and more complex geometries, increasing both the computation time and the operator time. Hexahedral grids effectively lower the computational run time and the required computational infrastructure, but at high cost in terms of operator time and minimal cell quality, especially when the computational analyses are targeting complex geometries such as aneurysm necks, severe stenoses and bifurcations. Moreover, such grids generally do not allow local refinements. As an attempt to overcome these limitations, a novel approach to hexahedral meshing is proposed in this paper, which combines the automated generation of multi-block structures with a grid-based method. The robustness of the novel approach is tested on common complex geometries, such as tree-like structures (including trifurcations), stenoses, and aneurysms. Additionally, the performance of the generated grid is assessed using two numerical examples. In the first example, a grid sensitivity analysis is performed for blood flow simulated in an abdominal mouse aorta and compared to tetrahedral grids with a prismatic boundary layer. In the second example, the fluid-structure interaction in a model of an aorta with aortic coarctation is simulated and the effect of local grid refinement is analyzed.
authors.affiliation: a Department of Flow Heat and Combustion Mechanics , Ghent University , Sint-Pietersnieuwstraat 41, Gent 9000 , Belgium.|b IBiTech-bioMMeda, Ghent University , Gent , Belgium.
authors.forename: Joris
authors.initials: J
authors.lastname: Bols
authors.affiliation: b IBiTech-bioMMeda, Ghent University , Gent , Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Taelman
authors.affiliation: b IBiTech-bioMMeda, Ghent University , Gent , Belgium.
authors.forename: G
authors.initials: G
authors.lastname: De Santis
authors.affiliation: a Department of Flow Heat and Combustion Mechanics , Ghent University , Sint-Pietersnieuwstraat 41, Gent 9000 , Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Degroote
authors.affiliation: b IBiTech-bioMMeda, Ghent University , Gent , Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Verhegghe
authors.affiliation: b IBiTech-bioMMeda, Ghent University , Gent , Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Segers
authors.affiliation: a Department of Flow Heat and Combustion Mechanics , Ghent University , Sint-Pietersnieuwstraat 41, Gent 9000 , Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Vierendeels
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000378:metabolism / Q000648:ultrastructure*; D006439:Hemodynamics; D051379:Mice; D008955:Models, Cardiovascular
keywords: biomechanics; complex geometries; computational fluid dynamics; fluid–structure interaction; grid-based method; hexahedral mesh generation