Tips & Tricks

CFD-GEOM Filters

Sometimes during the creation of a geometric model it is possible to have overlapping (duplicate) points, line, edges, and faces. This can also occur when CAD files are imported into CFD-GEOM. The user usually finds this situation when trying to do additional operations in CFD-GEOM.

Structured grid in a triangle using CFD-GEOM

CFD-GEOM can create a structured face on a geometry using four edge sets that form a closed circuit. If less than four edge sets are present for the geometry, for example three in a triangle, CFD-GEOM will create a degenerate face at the intersection of the first and third edge sets, as shown Figure 1.

Face Projection on a NURBS Surface in CFD-GEOM

CFD-GEOM provides a face projection tool that enables you to modify grid points such that they adhere to prescribed geometric surfaces. This option is very useful for cases where the underlying surface has curvature in two directions.

Using Parameters to Create Your Geometry in CFD-GEOM

Often, you need run several different cases where you need to modify one or more geometrical values where the overall shape of the entity is the same, only the size changes. In this case, it is useful to use CFD-GEOM scripting for your grid generation, rather than doing it interactively using the GUI.

Surface Trimming Utilities and Shortcuts in CFD-GEOM

CFD-GEOM provides several surface and trimming loop creation tools. Surface creation and trimming can be greatly simplified, depending upon what you want to do with the surfaces. In most of the cases, surfaces are used to generate unstructured triangular and quad meshes on trimmed surfaces.

Block coarsening in CFD-GEOM

One of the challenges of using structured meshes is that the grid resolution away from the region of interest is sometimes more than necessary. The Coarsen Structured Domains tool in CFD-GEOM provides a method to coarsen structured domains (also called blocks), thus reducing the mesh size and avoiding the use of arbitrary interfaces.

Viewing Your Model in CFD-GEOM

CFD-GEOM has many tools that can make viewing and manipulating your models easier. When you create your model, CFD-GEOM will show the handles for entities that are created. These handles are more like a wire frame representation of the model.

Mirroring Tools in CFD-GEOM

The mirroring tools provided in CFD-GEOM can help in the construction of symmetrical geometries or geometries involving repetitive parts. Ideally, we should take advantage of geometric symmetry to model just one-half or one-fourth of the model or even a 2D axi-symmetric model to reduce the computational time by significantly reducing the size of the model.

Advanced Blanking and Picking Tools in CFD-GEOM

Manipulating very large, complex models can be a challenging task, especially when small features of the geometry are included. CFD-GEOM has many advanced blanking/unblanking tools, as well as advanced picking tools, that can make dealing with large models easier.

How to Generate 3D Hybrid Meshes?

This tip will show you how to create a simple hybrid (structured/tetrahedral) mesh system. A hybrid mesh can be useful when part of the geometry is simple and the other part is to complex to use a structured mesh.