Pointwise Meshing – What's New and What's Coming
Pointwise Version 17.1 R4
Many of you have already had an opportunity to delve into the new capabilities in V17.1 R4 (released on 30 September), either through your own exploration and usage or via the webinar we held on 07 November.
Those of you who have not yet had chance to install and exercise V17.1 R4 will be interested to learn about everything awaiting you.
New and Updated CAE Solver Interfaces
The DLR TAU Code (tau.dlr.de) is now a supported computational fluid dynamics (CFD) solver. TAU is primarily used for aircraft configurations from subsonic to hypersonic flow regimes using hybrid unstructured meshes and an efficient parallel solver.
The existing native interface to OpenFOAM® has been upgraded with the addition of support for Sets and Zones. Three main reasons for using Sets and Zones with OpenFOAM are:
Collections of faces and cells are defined with the CAE, Set Volume Conditions command (Figure 1). How faceSets, faceZones, cellSets, and cellZones are exported is defined in the CAE, Set Solver Attributes command (Figure 2).
Finally, the existing CAE interface to the FDNS/UNIC solver was rewritten using Pointwise's recently-added plugin API for face-based mesh data.
Refined Grid Methods
Two improvements were made to the elliptic PDE technique for smoothing structured volume grids.
The option to compute spacing and angle constraints using data from an adjacent grid for face-based control functions has been added to the elliptic PDE technique for smoothing structured volume grids (Figure 3). This method of computation used to be available only for surface grid smoothing.
Also in the elliptic PDE technique for volume grids, we improved the manner in which a face with a floating boundary condition interacts with a non-floating face on which orthogonality has been specified. Now the orthogonality condition has a much stronger influence on the shape of the floating face so that it also emanates orthogonally from the non-floating face.
Users of the T-Rex (anisotropic tetrahedral extrusion) technique for hybrid meshing will appreciate how recombination of near-wall tets into prisms has been improved for “chains” of blocks – a blocking topology where several T-Rex volume meshes are stacked end-to-end. Instead of having to use a multi-pass process involving initialization of each individual block and than a final initialization of all blocks at once, a new multi-block recombination algorithm has been implemented that handles this in a single pass, greatly simplifying the workload.
Significant improvements in code performance were made to three commands.
Usability and Workflow Enhancements
Formerly, control points had to be deleted one at a time in Edit, Curve. This command has been updated so you can easily delete multiple control points up to and including all interior control points (Figure 4).
Finally, Pointwise is now compatible with the GridPro structured grid generation software from Program Development Co. Structured and unstructured domains can be exported from Pointwise to native GridPro formats for use as a faceted geometry definition. GridPro's volume grid format can be imported by Pointwise. This native format data exchange allows a workflow like the following:
Pointwise V17.2 – What's In-Work
The next major release of Pointwise will be V17.2 and at the time of this writing there are new features at various stages in our development pipeline. (Please read the important note at the end of the article.)
Let's first consider the completed features and have been fully tested:
These next features are complete from a development standpoint but not from a testing standpoint:
Figure 5: Draw Curves on the toolbar has been changed to a drop down menu. Your last selection becomes the default.
Several features are either still in development or development is just now beginning. This includes upgrading our CGNS support to v3 including the ability to export a file containing both structured and unstructured zones, a new assembly technique for complex volume grid topologies that will automatically assemble baffles and internal voids, and expanding our Linux support to include Ubuntu, Open SUSE, and CentOS.
Finally, the two marquee features planned for V17.2 will have a significant impact. However, there's a little bit more development to be completed and then a lot of testing.
Structured domains can now be used as true match boundary conditions for T-Rex. On export, with recombination enabled, the exposed quad faces of the recombined prisms from the viscous unstructured extrusion match the quad faces of the structured domain. Beyond the extrusion, pyramids are used to transition from the quad faces of the domain to tets in the unstructured block.
And the pièce de résistance – hex extrusion using T-Rex is being developed (Figure 7). As you know, the current T-Rex implementation starts from a tri mesh and extrudes layers of high aspect ratio tets that are post-processed into stacks of prisms. This upcoming major update to T-Rex will allow extrusion to start from a quad mesh and post-process the cells into stacks of hexes. All other attributes of the T-Rex technique will apply to this new scenario.
Your Next Steps
IMPORTANT NOTE: This article contains information that a publicly traded company might categorize as “forward looking statements.” We'll just say that the features described for V17.2 represent a snapshot of our current development pipeline. We cannot guarantee at this time when they'll be completed and released for production use. We will do our best to release them as soon as possible.