A Prismatic-Layer Advancing-Front Approach to Anisotropic Metric-Based Curved Mesh Generation

We present a strategy for generating curved, high-order, hybrid meshes that consist of a combination of prismatic layers close to the body and unstructured elements in the rest of the domain. Such curved meshes are required for high-order discretizations, but they are difficult to generate and adapt, in particular when anisotropic elements are desired next to curved geometries. To address the problem of possible inversions in this region, the proposed strategy grows prismatic, anisotropic layers of elements close to the geometry, using a metric to dictate the element sizing and starting with a metric-conforming surface mesh. The curvature of the elements attenuates as the layers grow, and the prismatic regions end once linear faces are possible. A linear unstructured mesh fills the remaining portion of the domain, and it is generated using a simple, metric-based advancing-front algorithm. The strategy is implemented in an adaptive solution process by using an existing mesh as a scaffold for metric evaluation. Results are presented for two-dimensional problems in an output-based adaptive setting. Comparisons with global remeshing show similar performance in output convergence, mesh quality, and aspect-ratio distributions and improved robustness and efficiency due to lack of a separate mesh curving step.