Geometry Tools ErrorAn attempt to generate additional parts failed owing to unspecified model problems

Mar 3, 2012

Issue:

On the Void Fill Geometry tool, the following error is issued after clicking the Fill Void button: 

Error: An attempt to generate additional parts failed owing to unspecified model problems

Solution:

Solution

The capping surfaces were created, but the void fill operation did not complete successfully after clicking the Fill Void button. This is a general error that means that Autodesk® Simulation CFD was unable to create the internal volume from the fully enclosed void.  

This is usually caused by a problem in the topology of the original geometry.

Because this issue is caused by a problem with the geometry, a good strategy is to use the Small Object Removal and Mesh Diagnostics to locate the issue: 

Step 1: Inspect and repair the geometry

Use the Edge Merging and Small Object Removal Geometry tools to identify potential problems. Some things to look for include:

  • Surfaces that overlap or are on top of one another
  • Tiny gaps between surfaces or volumes
  • Sliver surfaces
  • Tiny volumes resulting from volumes that overlap
  • Edges that are shared by more than two surfaces 

In some cases, applying Edge Merging and/or Small Object Removal can fix many of these problems. If they don't work, use the Mesh Diagnostics to try to identify problems, and return to the CAD tool to fix them.

Step 2: Look for very small edges using Edge Diagnostics

The Edge Diagnostics tool identifies edges that are smaller than the Minimum Refinement Length. (This means the edges that are really small.) Very tiny edges identified by this tool on the volume that you are trying to create may be causing the problem:

  1. On the Mesh Sizes dialog, click the Diagnostics button.
  2. Select the Edge tab.
  3. Slide the slider toward the left to progressively highlight the smaller edges.
  4. To write edge IDs that are problematic to a text file, click the Save to text file button. This creates a convenient reference when fixing the model in the CAD system.

Step 3: Inspect Surfaces using Surface Diagnostics

The Surface Diagnostics are a powerful tool for identifying problematic surfaces. Slivers, surfaces with "cusps," and other irregularities are identified with this tool. To use Surface Diagnostics:

  1. On the Mesh Sizes dialog, click the Diagnostics button.
  2. Select the Surface tab.
  3. Slide the slider toward the left to progressively highlight the smaller surfaces.
  4. To write surface IDs that are problematic to a text file, click the Save to text file button. This creates a convenient reference when fixing the model in the CAD system.

 

Products:

Simulation CFD

Versions:

2010;2011;2012;2013;2014

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