With its truly autonomous meshing capabilities CONVERGE automates the most time-consuming grid generation process for you. It not only simplifies your computational fluid dynamics (CFD) simulation workflow but also accelerates it. However, in CFD, problems rarely come with straightforward solutions. Despite the advantage, challenges in pre- and post-processing can still slow down one's analysis. Hence, to simplify things further, CONVERGE CFD software offers a wide array of tools with detailed documentation, all integrated into a single, user-friendly GUI, CONVERGE Studio. In this blog, we will explore the various CAD geometry preparation and manipulation tools integrated into CONVERGE Studio, which transform raw geometric data into simulation-ready models.
Importing and Preparing Geometries in CONVERGE Studio
Geometries in CFD simulations need to be watertight and hence involve some level of cleanup. In CONVERGE, these watertight geometries need to be supplied as surface files. Historically, geometries could only be imported as triangulated surface files in stereolithography format (.stl) for pre-processing in CONVERGE Studio. This added an extra step of exporting the geometry in .stl using the CAD tool in which the geometry was created. Although a simple step, it affected engineers who were obtaining geometries from dedicated CAD teams at their companies. To address this, we added a feature that allows users to directly import most CAD files in their native format and automatically triangulate them upon loading. Once imported, these surface files need to be cleaned to meet the required quality standards. CONVERGE Studio is equipped with all the necessary tools and utilities to identify geometry defects, clean, and, if required, modify geometries for simulations. Figure 2 highlights some of the geometry cleanup and diagnosis options in CONVERGE Studio.
Most of the surface manipulation tools are available for free when you purchase a CONVERGE license. For more complex and sophisticated surface preparation, CONVERGE Studio offers the Polygonica toolkit, which can be integrated and used with an add-on license, allowing you to perform more complex operations like coarsening over-refined surfaces (triangles), surface reconstruction, automated surface healing, etc., on your geometries. The toolkit also allows you to specify a batch of surface repair operations with Polygonica Job Launcher that can be applied to an imported geometry.
In addition to the above-mentioned utilities, for all the engine specialists who choose to simulate a sector of their engine geometries, CONVERGE Studio offers a utility to quickly create a properly prepared sector geometry based on a piston profile and a few geometric inputs.
New CAD Editor: B-Rep Modeling Within CONVERGE
With the official release of CONVERGE 5 a new CAD Editor module was introduced in CONVERGE Studio. Unlike the Case Setup module where the geometry preparation is performed on a triangulated geometry, this new module is based on the CATIA Geometry Modeling kernel, which uses the boundary representation (B-Rep) system. It is a more intuitive way of building and manipulating CAD geometries and is the most commonly used technique in several CAD softwares. Unlike STL files, B-Rep geometries represent a 3D object with a collection of surfaces that distinguishes the boundary between the interior and exterior of a solid. A big advantage of B-Rep is that it allows for non-manifold (over-lapping surfaces) sheets that are bounded by edges, which is particularly helpful for geometries with several interfaces (like battery packs). Figure 3 shows the CAD Editor interface in CONVERGE Studio.
In the CAD Editor module you can manipulate CAD geometries without the need to triangulate the surface first. The tool allows you to generate custom surface meshes for certain parts of the geometry, which can be further validated using the diagnosis tool available within the module. Once the geometry is prepared, you can directly transfer the geometry from the CAD Editor module to the Case Setup module to set up the case for simulation.
Conclusion
With a user-friendly interface, and comprehensive geometry manipulation tools, our team is making the best efforts to simplify and unify all of your CAD preparation and pre-processing operations under a single umbrella. Being an essential tool, capabilities in CONVERGE Studio are being continuously enhanced! Do not hesitate to connect with us to learn more about CAD pre-processing in CONVERGE Studio or to learn about the CONVERGE package as a whole.