“Hex cells are generally thought to provide the basis for a more accurate CFD solution, plus there will be fewer hexes than tets so computations would be faster. Fortunately, post-processing T-Rex’s tet cells into hexes (12 tets per hex) was a natural extension of the existing tet-to-prism combination algorithm.”
T-Rex (anisotropic tetrahedral extrusion) is a highly automated, advancing layer technique for generating a CFD mesh with boundary layer and wake resolution. The technique extrudes layers of high-aspect ratio, right-angle-included tetrahedra outward from a surface mesh. A post-processing operation sequentially combines three successive tetrahedra into a stack of prisms. In this new release of the technique, extrusion from a quadrilateral surface mesh begins with a single pyramid, after which the usual tet extrusion begins. The resulting tets (and that first pyramid) are post-processed into stacks of hexes.
This hybrid mesh for the X-38 re-entry vehicle was generated using the latest version of Pointwise’s T-Rex technique and consists of a layer of unstructured hexahedra (green) extruded off the quadrilateral surface mesh (yellow) and connected to the farfield tetrahedra (blue) by pyramids. The orange cells are hexahedra on the symmetry plane. Not shown are prisms extruded off triangles on the vehicle’s base. [View larger image]
“This new hex capability in T-Rex is just the first step of many that will vastly expand the scope of mesh types that Pointwise can generate,” said John Chawner, Pointwise’s president. “We look forward to customer feedback on this first release of unstructured hex cell generation in T-Rex to guide further developments.”
Pointwise Version 17.2 also includes updated compatibility with CGNS, FUN3D, ANSYS Gambit, STAR-CD, and SC/Tetra; support for the OpenSUSE, Ubuntu, and CentOS Linux distributions; several productivity improvements; and defect corrections.
Pointwise, Inc. is solving the top problem facing engineering analysts today – mesh generation for computational fluid dynamics (CFD). The company’s Pointwise software generates structured, unstructured and hybrid meshes; interfaces with CFD solvers, such as ANSYS FLUENT, STAR-CCM+, ANSYS CFX and OpenFOAM as well as many neutral formats, such as CGNS; runs on Windows (Intel and AMD), Linux (Intel and AMD), and Mac, and has a scripting language, Glyph, that can automate CFD meshing. Large manufacturing firms and research organizations worldwide rely on Pointwise as their complete CFD preprocessing solution.
More information about Pointwise is available at www.pointwise.com.
Pointwise is a registered trademark and Pointwise Glyph and T-Rex are trademarks of Pointwise, Inc. All other trademarks are property of their respective owner.