Unstructured and Hybrid Meshes: T-Rex, Pointwise's advancing layer technique for rapid generation of hybrid meshes, generates layers of near-wall, boundary layer resolving prisms and hexahedra.
Refinement and Adaptation: Clustering sources provide control of mesh resolution away from walls and near wakes, vortices, and other flow features. Point cloud sources provide the opportunity to adapt the mesh to your flow solution.
Block Structured Grids: Pointwise's block structured quadrilateral and hexahedral methods have been honed over decades to provide a broad suite of elliptical and hyperbolic PDE-based methods that generate grids with smoothness, clustering, and orthogonality.
Overset and High-Order Meshes: Whether your mesh is structured, unstructured, or hybrid, you can generate it for use with an overset flow solver using the built-in interfaces to overset grid assemblers. If you use a high-order flow solver, you can utilize Pointwise's degree elevation and mesh curving capabilities.
Pointwise is the workhorse that moves you confidently from repairing less-than-perfect geometry models to preparing the grid and boundary conditions for your flow solvers. You can work with the prevalent types of geometry models in use today.
Most importantly, Pointwise gives you access to tools that ensure your geometry model is watertight and ready for meshing.
Once your mesh is complete, you export it and its boundary conditions to the CFD solver format of your choice. Interfaces are available to more than 50 open-source, proprietary, and standard formats. If your solver format is not included, you can use Pointwise's CAE Export Plugin capability to add it easily.
Any or all of your mesh generation process can be automated with Pointwise's Glyph scripting language. You can write fully-automated, top-down meshing templates. You can encapsulate your best practices in convenient macros for frequently used operations.
Pointwise's commitment to your success goes beyond just the software. Led by our industry-tested engineers, our technical support team is ready to provide assistance and software training to help you come up to speed fast. Pointwise generates more than just grids – we build long-term, collaborative relationships.
Geometry modeling is the solid foundation upon which your mesh is built. With Pointwise, the geometry model from your design software can be imported accurately, made meshable (the geometry repair and clean-up process), and robustly and reliably meshed.
Geometry models from contemporary Mechanical CAD (MCAD) software are comprised of non-uniform rational B-Splines (NURBS) in a Boundary Representation (B-Rep) topology. These geometry models can be imported from a variety of formats including standards such as IGES and STEP.
B-Rep NURBS geometry models can exhibit a lack of watertightness. In other words, there can be gaps between surfaces and surfaces can overlap. The source of gaps and overlaps are the inexact, tolerance-based topology operations that MCAD software employs to create complex models out of relatively simple geometry. (For more information on this topic, see Why CAD Surface Geometry is Inexact on Pointwise's Another Fine Mesh blog.) Fortunately, Pointwise includes two feature suites for handling this situation.
Pointwise's Solid Meshing suite of features is designed to avoid gap problems from the start. By assembling the geometry model into a watertight solid, meshing can proceed without a hitch. You can assemble solids automatically during geometry model import, which is handy for models you are very familiar with. For other geometry models, you can assemble a solid manually and interactively.
An important component of Solid Meshing is the use of virtual topology called quilts. The geometry model's original topology is the result of modeling operations in the MCAD software and not necessarily a result of design intent. A quilt is simply a region you want meshed with a single mesh. Quilts provide a mesh topology that is completely independent from the geometry model topology while still adhering to its shape. You can assemble quilts during geometry model import and quilts can be assembled manually and interactively.
With Fault-Tolerance Meshing, the geometry model is not assembled or modified in any way. You mesh the geometry model as-is. You follow this initial mesh creation with a technique called Merging that heals the mesh across gaps in the geometry model. After the meshes have been merged, the meshing algorithms remove artifacts such as slivers and seams.
In this video you will see how geometry models are prepared for mesh generation including geometry creation and editing and the strategies available to you for identifying and healing gaps.
This video demonstrates techniques that simplify working with a complex geometry model as you prepare it for meshing.
Geometry models for use in Pointwise can be comprised of facets formed into surfaces called Shells. These faceted or discrete geometry models can be imported from STL files and several other formats.
Relative to B-Rep NURBS geometry models, faceted models are simple because they lack topology. They are just a mesh with which we are all familiar. However, that strength is also a weakness because in order to accurately represent the geometry model with the mesh you need to respect its feature lines (also known as hard edges). Pointwise provides Feature Extraction, the ability to identify feature lines in the shells based on the relative turning angle between adjacent facets. Once identified, feature lines can be used to split the shell. Feature extraction can be performed automatically during geometry model import or interactively on any portion of the geometry model.
There are times when you need to add to the geometry model you imported. When simulating a wind tunnel test, you will often need to create tunnel walls and model supports. Even in free air you may need to generate farfield shapes. In cases when part of the geometry model does not import properly you will need to replace it. And there are instances where you want to create a simple geometry model from scratch. Pointwise provides a variety of curve and surface creation tools to support these activities.
|Revolved Surfaces||Ruled Surfaces||Coons Surfaces||Sweep Surfaces||Fillets||Planes||Lines|
What you need from a mesh is both simple (complete coverage of the wetted surface and fluid volume with positive volume cells) and complex (balancing resolution and cell shape metrics). Add to those general needs the specific requirements of your flow solver, and you need meshing software that provides both flexibility and control so that the meshing process is robust and reliable.
That's why Pointwise includes a variety of meshing techniques from automated to manual, from structured to unstructured to hybrid, from 1D to 2D to 3D, from Delaunay to advancing layer to elliptic PDE to overset and high-order, all implemented in a multi-block or multi-zone strategy.
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. These anisotropic tetrahedra in the near-wall and near-wake regions are then combined into stacks of prisms or hexahedra. Away from the geometry model, you can use either isotropic tetrahedra or Cartesian hexahedra called Voxels.
Prism and hexahedral layers can also be generated via traditional extrusion methods that follow normal, linear, rotational, or user-defined paths. Tunable controls let you adjust step size, mesh quality, and smoothing of the extruded layers.
Learn strategies to quickly construct a high-quality viscous mesh for a model aircraft propeller. These strategies can be used to accurately capture relevant blade geometry as well as efficiently resolve the surface curvature and boundary layer.
This case study summarizes how a T-Rex hybrid grid showed up to a seven-fold improvement in solution efficiency compared to other approaches in predicting thrust and torque.
Discover how to create unstructured hexahedra quickly on complex geometry using T-Rex (anisotropic tetrahedral extrusion). Best practices for the generation of both surface and volume meshes and troubleshooting techniques are shown.
Clustering to flow features away from the geometry model can be obtained using Sources. These geometric regions (like boxes, cylinders, and spheres) are sketched onto the grid and a length scale is applied. The mesh will be refined to match the length scale within the shape. A special type of source based on a point cloud is used for mesh adaptation. The flow solver provides a length scale at each point in the cloud, which in turn, is used to refine the mesh.
Pointwise's structured quadrilateral and hexahedral grid techniques have been honed continuously since 1984 to generate the best quality grids with the ultimate in control over smoothness, clustering, and orthogonality. Pointwise's elliptic PDE 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. And the surface formulation of the elliptic PDE methods allows for surfaces to be constrained to the geometry model 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. All of the extrusion methods also can be applied to 2D grids and surface grids constrained to the geometry model. 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.
In this video you will see a diffusing serpentine inlet used to demonstrate some of the more advanced structured gridding techniques available in Pointwise.
This case study describes how structured grids can provide the high accuracy and low cell count required for marine applications.
Using Pointwise's integration with two overset grid assembly (OGA) software tools, you can now execute the entire overset 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 capabilities include:
Pointwise is on the leading edge of research and development in the area of high-order mesh generation to support high-order flow solvers. Any linear mesh can be elevated up to polynomial degree 4. Most importantly, the surface mesh cells will be curved to match the shape of the geometry model. That curvature is then blended into the volume mesh's interior in order to prevent cell crossing.
This case study describes how Pointwise supports the use of overset grids for advanced CFD applications.
This video demonstrates the process of generating overlapping grids, setting up and executing Suggar++, and exporting the domain connectivity information all from within Pointwise. We demonstrate an overset flow simulation using the Caelus CFD solver.
This video shows how Pointwise overcomes the challenges associated with degree elevation of linear elements: boundary conformance and curving of high aspect ratio cells.
Your verification and validation activities have resulted in best practices for the type of mesh needed to get a converged and accurate CFD solution. Those best practices included thresholds on various mesh metrics. That is why Pointwise includes tools that provide both global and local views of mesh quality. Cutting planes can be used to dissect the mesh to see the interior, and graphical tools can be used to zoom in on the cells with the minimum and maximum metric values.
Rules are a global technique for proactively monitoring mesh quality. You can define the acceptable values of any metric. 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.
Your CFD process is unique: your product, a specific suite of software, a unique set of best practices, and a proprietary set of performance goals. In order to best support your use of CFD, you need software, including your mesh generator, to include robust tools that can be tailored to your process.
Pointwise's scripting language, Glyph, covers the entire range of functionality in the user interface. This allows you to capture the unique manner in which you generate meshes and make it part of your organization's intellectual property.
Pointwise maintains the Glyph Script Exchange on GitHub, 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 starting point for your own script development. Once you start writing your own scripts, be sure to contribute some of them to the Exchange.
This video demonstrates appropriate meshing strategies while automating the grid generation process using Glyph scripting on the NASA Common Research Model.
This video shows how you can configure the Glyph Server in Pointwise and add support for scripting languages including Python.
Pointwise supports neutral, native, and de facto standard interfaces to CFD solvers and other popular CFD formats to ensure a seamless fit with your CFD process.
|AcuSolve||ADPAC||ADS||Aero-F||ANSYS CFX||ANSYS Fluent||CFD++||CFDShip-Iowa|
In addition to generating the mesh, support for your flow solver extends to boundary conditions, volume conditions, and other solver data. You can apply BCs and VCs throughout the mesh to setup your computation, which will be used to properly export the mesh file or files for your solver.
Using Pointwise's CAE Plugin SDK, you can write your own custom exporter. Instead of using a neutral format like CGNS or borrowing another solver's file format, you can use the SDK to write your unique file format. Once written, you simply place the plugin in a folder in Pointwise's installation location, and your solver will appear in the user interface the next time you run Pointwise. A plugin is perfect for new codes, research codes that change frequently, or proprietary formats for which you want to limit use.
We invite you to share the plugin for your CAE plugin on Pointwise's GitHub Repository. This will give you the ability to share updates with your research collaborators around the globe, so they are always using the latest version of your plugin. We have already published the source code for several plugins on GitHub for you to use as a learning tool.
Plugins are not limited to writing the final mesh and its boundary conditions to a CFD solver format. Sometimes you need to export the mesh or a portion of it to a specific file type. Conversely, sometimes you have old meshes that you want to import into Pointwise.
Rather than translating those meshes to and from file formats for which Pointwise has built-in compatibility, you can use Pointwise's Grid Import Plugin SDK to write a reader for your mesh's file type. Just like for CAE plugins, you are invited to share your grid import plugins on Pointwise's GitHub repository.
Customizing the software by adding your own file importer or exporter has never been easier with this guide to writing plugins.
This video provides an overview of how to write your own plugin using Pointwise's application programming interface (API).
Pointwise supports the most popular desktop workstations in use today by CFD practitioners: Microsoft Windows, Linux, and macOS. It supports each platform's native look-and-feel and provides 3D graphics through the OpenGL industry standard. And Pointwise's native project file is portable across all supported platforms.
|Windows 8.1||CentOS 7||El Capitan 10.13|
|Windows 10||Red Hat Enterprise Linux 7.4|
|SUSE Enterprise Linux Desktop 12.3|
|Ubuntu Desktop 16.04|
It is recommended that the computer on which you plan to run Pointwise has the following characteristics.
It is important to note the following.