CAD Preparation for your CFD Simulation

For numerical investigations, the geometry or design of interest, that is going to be analyzed, has to be modified for CFD analysis. Depending on the used numerical analysis software, the CAD data preparation needs to be done carefully. The most important step during a numerical analysis is the mesh generation. This is highly related to the used CAD data and should not be underestimated. Especially, if one is using the known meshing tool named »snappyHexMesh«.

The CAD preparation does have different properties. For example, non-necessary details are commonly removed. Thus, the amount of numerical volume elements are reduced which increases the calculation speed. Furthermore, CAD geometries might be extreme large (dimensions / size /  areas) while only a defined area of interest should be analyzed. The CAD preparation limits the area of interested. Additionally, in some cases, CAD data are not usable for CFD analysis, e.g., if a pipe system consists of several single solid blocks. Again, here a CAD preparation has to be performed.

The CAD preparation guarantees the basic skeleton for the meshing step. If the CAD geometry is not optimized, different and non-expected results might be an outcome of the meshing step.

Holzmann CFD offers the re-creation, fixation, and simplification of your CAD model for your numerical analysis. If the meshing tool from the open-source software toolbox OpenFOAM® is used, well-prepared CAD data are essential to reach the mesh quality parameters.

Holzmann CFD uses different software packages to build your CAD model for your numerical analysis. The pre-processing of the CAD data, as well as the meshing step, are the most crucial operations during a CFD analysis.

Preferred CAD formats for repairing are STEP, BREP, and IGES files. STL files are possible but require much more investigation.

Repairing of the Ghostbuster CAD Data