Issue link: https://resources.system-analysis.cadence.com/i/1472753
Fidelity Pointwise Grid Cell Remediation Method for Overset Meshes 3 www.cadence.com The best approach to orphan remediation is to refine candidate donor cells, although the outcome is far from certain (in some cases the number of orphans is increased). In fact, the issue is highly dependent on the near-body (viscous) and background (inviscid) component grids within a single composite grid. Typically, the fringes (locations receiving foreign data) in component grids are created to capture near-body physics. Conversely, far-field or background grids are typically created to fill space uniformly, without much regard for near-body physics. Background grids are ideal for donor cells (cells providing solution data) and orphan donor candidate cell modifi- cation. In the current method, the user can select cell categories (fringes, donors, and/or orphan donor candidates) in the local mesh that are to be modified. Target length scale determination begins by calculating the local average edge length for each vertex in the mesh. If the local cell is scheduled for modification, based on user settings for the category, the foreign cell's geometry defines the target length scale. Grid Cell Remediation in Structured Meshes Structured, or mapped, meshes have long been used for the numerical solution of partial differential equations. With struc- tured meshes, a physical region is divided into an ordered collection of hexahedral cells that logically connect to a computa- tional matrix. There are many advantages to this form that have sustained structured grids as a popular and powerful meshing framework, including the reduced overhead and memory due to the implicit connectivity between cells and the inherent solution accuracy with hexahedral cells that are generally aligned with the principal flow directions. Unfortunately, there also exist complications with structured grids, with perhaps the biggest being the difficulty in automating the construction of structured meshes on complex geometries. A well-proven method for discretizing general regions with structured meshes is the multi-block approach. The relatively high level of effort required to create a general multi-block structured grid has allowed other methods to gain in popularity. Though many overset tools now accept meshes of a more general type, the structured mesh continues to be a workhorse for the overset meshing industry. Figure 3. Five block structured grid sphere