Unstructured Hexahedral Mesh Based on Conduction Temperature Distribution

Seung Lee, Massachusetts Institute of Technology

Over the past two decades, the fluid mechanics of blood flow has been shown to play an important role in arterial adaptation and disease localization. For numerical studies, it is important to use the true geometry of the arterial bifurcation in order to accurately represent in vivo curvature and variable diameter. Here, we describe a technique to generate high quality, unstructured, hexahedral mesh appropriate for spectral element simulation in bifurcation geometry based on conduction temperature distribution. The first step is to process the medical images to extract the geometry data, which is then smoothed with non-shrinking Fourier algorithm. Next, the smoothed data is used to create a preliminary mesh with any commercial meshing code. The main objective of the preliminary mesh is to preserve the surface information, whereas the mesh quality is not as important. In the third step, three separate conduction problems are solved within the bifurcation geometry using the preliminary mesh. For each conduction problem, temperatures are specified at two branch tips with the values of one and zero, while the third branch tip is insulated. The final step is to use these isosurfaces to generate bounding surfaces for “slabs” of hexahedral elements. The isosurfaces are guaranteed to be non-intersecting and orthogonal to the wall, thereby producing a high quality hexahedral mesh.

Abstract Author(s): Seung E. Lee