Mesh quality is the key to converged and accurate CFD solutions especially for viscous flows over complex geometry. With Pointwise, you get all the tools you need to achieve the desired results – high levels of automation plus intimate levels of control. Pointwise's structured grid techniques are the best available and our T-Rex technique for hybrid, boundary layer resolving meshes automates the rapid meshing of complex shapes. At the other extreme, you can even move grid points one at a time if that is what you need.
Pointwise is the workhorse that moves you confidently from dealing with less-than-perfect geometry models to formatting the grid for your flow solvers. Using our proprietary geometry kernel, you will import geometry models from native CAD and standard formats, work with both analytic (NURBS) and faceted (STL) geometry representations, and ensure that your geometry is watertight and ready to mesh with fault tolerant meshing and solid meshing.
Once your mesh is complete, you will export it and its boundary conditions to open-source, commercial, and standard CFD formats such as CGNS. And if Pointwise does not have built-in support for your preferred file format, you can add your own exporter with Pointwise's CAE Export Plugin SDK. Even the meshing process itself can be customized with templates and macros you write in our Tcl-based Glyph scripting language.
Our commitment to your success is only beginning with your Pointwise license. Whether you encounter a technical issue or just need advice to get the most from Pointwise, our industry-tested engineers are ready to help. Support and training are included with every license. We generate more than just grids – we are building long-term relationships.
Pointwise's proprietary geometry kernel supports hybrid geometry so that you can work simultaneously with analytic (NURBS) or discrete (faceted) surfaces. Geometry models are imported from CAD native, neutral, and standard file formats.
Myriad issues can result in geometry models that are less than watertight, leaving gaps between surfaces that are large enough to cause problems for meshing. Pointwise's Solid Meshing suite of features is designed to avoid these types of problems from the start. By forming the geometry model into a watertight solid, gaps are closed implicitly so that meshing can proceed without a hitch. Pointwise has implemented a broad range of solid modeling operations, some that are performed automatically during geometry file import and others than can be fine-tuned for just a portion of the model.
An important concept in Solid Meshing is the quilt, a subregion of the geometry that reflects the design intent (for example, the hood of a car or the upper surface of a wing) that will be meshed as a single unit regardless of the number of geometry surfaces supporting it. At its simplest, every trimmed surface in the geometry model is a quilt. But assemble adjacent trimmed surfaces into a larger quilt and your mesh topology will be simplified.
Both solid model and quilt assembly can be performed automatically during geometry model import.
When technical reasons or personal preference prevent you from applying Solid Meshing, Fault-Tolerant Meshing is your alternative. A technique called merging automatically identifies adjacent surface meshes, joins them across geometry model gaps, and uses the mesh solver to remove geometry artifacts such as topology and sliver surfaces from the mesh.
When working with faceted geometry, it is often necessary to recover the topology of the geometry so that feature lines (also known as hard edges) are reproduced accurately in the mesh. Pointwise provides feature extraction, the ability to identify feature lines in the faceted surfaces based only a turning angle. Feature extraction can be performed automatically during geometry import or interactively on any portion of the geometry model.
Shell entities (the surfaces in a faceted geometry model) can be intersected just like any other geometry entity in the model. They can also be split by cutting them with planes, both constant coordinate planes and any arbitrarily oriented plane you create.
Pointwise does not require a geometry model for meshing – the mesh can be created directly in 3-D without having to create geometry first. This feature lets you use geometry from CAD only where necessary. Furthermore, Pointwise's built-in geometry modeler may be used to supplement what is imported from a CAD system or create new models from scratch.
|Revolved Surfaces||Catmull-Rom/Akima splines|
|Sweep Surfaces||Offset Curves|
When meshing complex geometry models, Pointwise can create meshes that are independent of the model's surface topology. A mesh may span an entire surface, only a portion of a surface, or multiple surfaces.
Pointwise's T-Rex (anisotropic tetrahedral extrusion) is an advancing layer technique for extruding regular layers of high-quality (right angle included) tetrahedra from boundaries. The algorithm adjusts to convex and concave regions and colliding extrusion fronts.
An optional step combines tetrahedra in the near-wall and near-wake regions into either prisms or hexahedra. The resulting mesh has a lower cell count than the raw tetrahedral mesh which improves computational efficiency. But this cell combination also creates higher quality cells in the regions where accuracy is most important.
Prism layers can also be generated via traditional extrusion methods that start with an unstructured surface mesh and follow normal, linear, rotational, or user-defined paths. Tunable controls let you adjust step size, mesh quality, and smoothing of the extruded layers.
Hexahedral and tetrahedral meshes can be interfaced in several ways to form a hybrid grid. Structured hexahedral and unstructured tetrahedral blocks can be indirectly interfaced by a point to point conformal interface with hanging edges. Direct hexahedral-tetrahedral interfaces are created through automatically generated pyramid cells.
Extruded prism blocks interface with tetrahedral blocks either directly (on the triangle faces) or through automatically generated pyramids (on the quadrilateral faces).
Unstructured grids consisting of triangles and tetrahedra are generated by a modified Delaunay method. Like structured grids, unstructured surface grids can span multiple entities in the geometry model and adhere to the CAD model automatically. The unstructured solver may be re-applied at any time, giving you control over minimum and maximum cell size, maximum cell-to-cell turning angle, maximum surface deviation, and boundary decay.
Pointwise's structured quadrilateral and hexahedral grid techniques are the best available and have been honed continuously since 1984 to generate the best quality grids with the ultimate in control over smoothness, clustering, and orthogonality.
The software begins with transfinite interpolation (TFI) algebraic techniques that automatically account for adherence to the geometry model where necessary. Several formulations of the TFI method are available including standard, linear, polar, and parametric.
The cell quality of structured grids can be significantly improved by applying Pointwise's elliptic PDE methods. These methods iteratively solve Poisson's equation with control functions that can be fine-tuned at any time using the following techniques.
Several formulations of the wall angle and wall spacing constraints are available with the von Lavante-Hilgenstock-White and Steger-Sorenson methods to ensure grids that meet your needs for how transverse grid lines meet boundaries.
The elliptic solver methods also feature support for several boundary condition types depending on whether you need the boundary points to remain fixed, slide along the shape, or float with the PDE solution.
The surface formulation of the elliptic PDE methods allows for surfaces to be constrained to the CAD geometry whether that be a single surface or span a collection of surfaces.
Structured grids with high degrees of orthogonality and clustering control can also be created using Pointwise's hyperbolic PDE and algebraic extrusion methods. The extrusion methods start with one or more structured quadrilateral surface grids and extrude hexahedral volume grids. The extrusion can generate one volume grid per surface grid or surface grids can be grouped into larger faces for extrusion into a single block.
All of the extrusion methods also can be applied to 2-D grids and surface grids constrained to CAD surfaces. In the latter case, the mesh marches across the entire geometry model, from one surface to the next.
The hyperbolic method is especially well suited for CFD solvers that use overlapping grids but contains features to extrude multi-block abutting grids as well. In other words, a point to point interface can be maintained between adjacent abutting blocks.
Pointwise has always been able to generate both multi-block abutting and overset grids. With the software's integration with two overset grid assembly (OGA) software tools, you can now execute the entire assembly process, sometimes known as hole cutting, from within a single software product instead of using a chain of other tools. From Pointwise you can launch OGA software for selected grids, import the results of the OGA computations, and visualize the resulting parameters of interest for your overset grid.
Pointwise's overset grid assembly capabilties include:
Mesh quality is where you have the largest impact on solution quality - after all, the numerical algorithms and physical models are dictated by choice of the solver. A high quality mesh increases the accuracy of the CFD solution and improves convergence relative to a poor quality mesh. Therefore, it is important for a mesher to provide tools for obtaining and improving a mesh. Some meshing software uses hundreds of unnecessary blocks as a crutch to obtain a decent mesh. Pointwise's mesh methods, on the other hand, have been honed through years of application on analyses for which accuracy, and hence mesh quality, are critical.
Mesh quality tools in Pointwise keep you in control of mesh metrics relative to your acceptance criteria. Metrics can be examined graphically in great detail down to the cell-to-cell level. Cutting planes can be used to dissect the mesh to see the interior, graphical tools can be used to zoom in on the cells with the minimum and maximum metric values, and simply pointing at a cell will display its metric value.
|Jacobian||Smoothness I||Volume||Smoothness J|
|Component Volume||Smoothness K||Area||Minimum Included Angle|
|Length||Maximum Included Angle||Length I||Equiangle Skewness|
|Length J||Equiarea Skewness||Length K||Equivolume Skewness|
|Volume Ratio||Centroid Skewness||Area Ratio||Wall Spacing|
|Length I Ratio||Wall Orthogonality||Length J Ratio||Database Associativity|
|Length K Ratio||Boundary Proximity||Aspect Ratio||Surface Proximity|
Rules can be applied to proactively monitor the mesh quality. You define the acceptable values of any metric function (for example, minimum included angle must be greater than 5 degrees). Then as you are creating the mesh, pressing one button at the top level of the interface will immediately display all grids that violate the rule.
Pointwise's Tcl-based scripting language, Glyph, provides customization capabilities for both the experienced analyst and the design engineer. The meshing process can be customized for your particular class of configurations or the software can be made to do things it was not designed to do.
The experienced analyst will find that Glyph's commands cover the entire range of functionality available in Pointwise's GUI, allowing tricks and special techniques to be captured and made part of your organization's intellectual property. Design engineers will appreciate the fact that Glyph can be used to create customized meshing applications for specific configurations, allowing them to automatically generate a mesh and apply CFD.
Rather than type scripts entirely by hand with the help of the documentation, you can use journaling. When journaling is enabled, a Glyph script of all your interaction with the GUI is exported to a file for later editing and playback. As a learning tool you can also enable the echoing of script commands to the messages window.
Pointwise maintains the Glyph Script Exchange, an online repository of scripts developed by ourselves, our partners, and our customers. These freely available scripts not only immediately provide you with new capabilities, but can form the basis for new scripts through your editing and updating. They are a great learning tool. Once you start writing your own scripts be sure to contribute some of them to the Exchange.
Pointwise supports neutral, native, and de facto standard interfaces to CFD solvers (including the specification of solver boundary conditions) and a variety of other formats to ensure that Pointwise fits into your CFD process. Of course, Pointwise is compatible with a variety of CAD data formats as well.
Pointwise supports these native CFD and CAE formats:
Pointwise supports the latest version of CGNS, the CFD data standard, including the ability to write structured and unstructured zones to the same file.
Pointwise's CAE Plugin SDK is how you could write your own custom exporter of grid and boundary conditions. Rather than utilize a neutral format, a CAE plugin can be written to provide exactly the format you need. A plugin is perfect for research codes that change frequently or proprietary formats for which you want to limit use.
Pointwise supports the most popular desktop workstations in use today by CAE engineers. The application supports each platform's native look-and-feel and provides 3-D graphics through the OpenGL industry standard. Pointwise's native project file is portable across all supported platforms.
Mac OS X
*There is a known incompatibility on Microsoft Windows between Dell Backup & Recovery software and Pointwise V18. If you experience problems opening or saving a file from Pointwise, Dell Backup & Recovery software should be disabled or uninstalled.
|Red Hat Enterprise Linux||6|
|SUSE Enterprise Linux Desktop||12 SP1|
Listed below are the specific versions of library packages that we have on our test machines where we know Pointwise works. Other dependences (e.g. libGL) are not explicitly listed below as they should be part of any standard install that includes the packages listed below.
Important: Pointwise V18.1 R1 will not support Mac OS X versions older than 10.10.