Error Message—Model does not Product an Integer Symmetric Pattern
The following error message is issued for a radiation analysis that has symmetry boundary conditions:
Error: The model does not produce an integer symmetric pattern
This error happens when the angle subtended by the model does not produce an integer number of objects when the slice is "revolved" 360 degrees.
A 21 degree wedge is built and the appropriate faces are assigned with symmetry boundary conditions.
The following calculation is performed:
number of pieces = 360 / 21 = 17.1429
The 0.1429 fractional piece will cause this error.
The correct way would be to use a 20 degree angle. The calculation would be 360/20 = 18 pieces.
The number of pieces is important, since Autodesk® Simulation CFD actually creates the virtual pieces and deals with the entire geometry to correctly model internal shadowing.
To resolve this issue:
Modify the geometry in the CAD tool to ensure that it sweeps an angle that is a factor of 360.