Discussion Forum

Hey all,

First off: I am completely new to Comsol. So please don't be too mad at me, if there is an obvious solution to what I am asking.

I am trying to create a mesh on a screw of a screw conveyor. I have an .mph file (attached) of the screw consisting of 22 parts (approx. one part per turn). After importing the file I both repair and convert the model to a Comsol Object. When trying to initialize the mesh, though, I get the following error message:

Exception:
com.femlab.jni.FlNativeException: An empty cavity was generated
Messages:
An empty cavity was generated

Failed to insert point
- s1 value: 38
- s2 value: 3.05024e-007

Failed to generate mesh for face
- Face: 107

Stack trace:
at delaunaytri.cpp, row 586, ()
at delaunaytri.cpp, row 823, ()
at mesh3init.cpp, row 3868, ()
at com.femlab.mesh.Mesh.init(Native Method)
at com.femlab.mesh.Mesh.init(Unknown Source)
at com.femlab.mesh.MeshInitRunnable.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.util.j.run(Unknown Source)
at com.femlab.util.ae.run(Unknown Source)

However, when deleting all but one screw part the mesh is created without complaint and the analysis carried out all smoothly. The error occurs whenever more than one screw part is to be processed. Merging the parts to one and deleting all inner boundaries didn't do the trick.

PS: I uploaded only two parts of the screw due to the file size limit. However this will do as a MWE. Processing both parts will result in the above-mentioned error. Using only one part won't.

I appreciate any help you can give.

All the best.