Polyflow does not accept the mesh
 

Hello,
I want to model a high viscous flow through a conical die with Polyflow.
I double checked the setup and adjusted the mesh again and again - but I always receive the same Error-message.
The calculation didn't converge because of bad shaped elements.
Here is the original message:

Summary of the simulation:

The computation failed.

* Expert tool diagnostics *
The problem F.E.M. Task has not converged.

* Expert tool advice in order to optimize the simulation *

At least one bad element has been detected in the mesh.
The worst has the following feature(s)
Too small angle in element 276439, (x,y,z) = (0.027134,
8.2309e-005, 8.2309e-005).
This can lead to local inaccuracies and possibly convergence
difficulties. It is strongly recommended to fix the mesh.


I checked the location of the bad element, it is a different Element with every new setting of the mesh.
Unfortunatly I have no ideas how to fix this - the initial mesh looks appropriate to me.
I used a hexaeda mesh (and also checked a triangular: same message), the remeshing locations I set for either the whole geometry (pipe + jet) or just the extrudate.
The problem stays.

Hast anyone an idea how to tell polyflow that the mesh is alright?

Many thanks!
Jasmina

... For a better remeshing I also checked the "generate a sliceable free jet" - option. this helped for one setting, but after a small change in other settings (e.g. material data, meshing) the error message (see above) appeared again.
Maybe someone has an idea why..