PumpLinx® and Simerics® MP include an automated mesh generator to facilitate the fast and easy generation of high quality grids for efficient use by the CFD solvers. This grid generator uses a proprietary geometry Conformal Adaptative Binary-tree (CAB) algorithm. CAB generates cartesian hexahedra cells in a volume enclosed by a group of “Water tight” surfaces. Close to the boundary, CAB will automatically adjust the grid shape to conform to the surfaces and critical geometry edges. In order to fit critical geometrical features, CAB will automatically adjust the cell size by progressive division of the mesh cells in half (binary grid). This is a highly efficient means of resolving fine features with minimum of mesh cells. Besides this grid generation tool, PumpLinx also provides users with an automated structured grid generator for special components such as the rotors of positive displacement pumps.
CAB’s unique features include:
Automated and Fast Grid Generation:The user picks a group of enclosed surfaces, then clicks a button and the mesh is generated automatically. For a typical engineering problem, the grid can be created within minutes.
Accurate Representation of Original Geometry:The CAB generated mesh fits the surface shape at the volume boundary. The mesh also preserves other critical geometry features such as important edges. CAB will automatically increase grid density to better resolve geometry features. Users can also explicitly set grid density/surface curvature to have direct control over grid quality.
High Quality/High Efficiency Grid:Grids generated by CAB are mostly cartesian hexahedra cells which are very preferable for many high accuracy algorithms. For the same level of accuracy, fewer cells are needed as compared to tetrahedral cells.
Can Tolerate “Dirty” CAD Files:Many CAD surface files are not fully water tight. They might have small gaps, or are not properly stitched together. Many grid generation algorithm will fail if the CAD geometry contains such “dirty” features, and the geometry has to be cleaned up before grid generation. However CAB algorithm can tolerate those dirty geometry to a certain degree. In many cases, CAB can still generate a reasonable grid from dirty geometries with only a negligible lose of accuracy, allowing meaningful simulation of the problem.