Preparation of Geometry Models for Mesh Generation and CFD
13 www.cadence.com
Translation errors (described above) will often result in holes where certain entities within the model cannot be imported.
These cases require tools for covering those holes with surfaces that can best approximate the true shape of the missing
component.
[The refeaturing of geometry models imported from STL has to recover the sharp edges and feature lines so that they may be
accurately reproduced in the mesh. In addition, it is useful to reduce the density of the facets by merging them where they are
coplanar. https://youtu.be/iIXjNcczqyY]
Discrete geometry models present an interesting case of insufficient detail. A benefit of discrete geometry models is that they
lack topology, a main complicating factor in using analytic B-Rep models. At the same time, the lack of topology in a discrete
model hampers their use. Without topology, the model is a "triangle soup" when, in reality, the modeled object has distinct
geometric features likely significant to the CFD simulation. Therefore "refeaturing" of discrete models becomes a useful tool.
The facets in a discrete model can be assembled into surfaces bounded by feature lines (aka hard edges). These hard edges
can be defined by the relative turning angle of the facet normal vectors on either side of the line.
Summary
Geometry modeling is a competent field of technology representing a broad range of established and emerging technologies.
The models produced by geometry modeling software are essential for CFD applications. The use of geometry models for
CFD can be streamlined by understanding a few essential factors and utilizing tools that best handle them.
References
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