Tetulator failed: face already in front

I have been playing with Caedium for the last couple of weeks and was able to run my own simple simulations. As of now though, I'm stuck with a model with a more complex geometry, getting the message "Tetulator failed: face already in front". I looked at all the tutorials and FAQ, and even found the mes/tetulator preference panel, but no reference info on how to play with those parameters. Any hints? Is this a problem with the meshing procedure or with my model, or both? How can it be fixed?
Thanks in advance for your support.

Mismatch Between Surface Mesh Element Sizes

I think the likely problem is a mismatch between the surface mesh element size either side of a small gap and/or under resolution of certain geometry features. You shouldn't need to change the Tetulator preferences.

To visualize volume element quality (even on a failed mesh):

  1. For the volume, set the Style = Flat and Transparent = Off
  2. Drag and drop the Scalar Fields->Vol Ratio from the Results Tool Palette onto the volume
  3. Use the threshold sliders in the View Legend to reduce the displayed elements to the lower range. (0 = planar, 1 = perfect). For more details see "View a Mesh"

If you have a few randomly scattered poor elements you are usually OK, but if there are clumps near the surface then you are likely to have trouble. Another indication of poor mesh elements is having to reduce the relaxation factors. For more details see "Relaxation Factors in RANS Flow Solvers".

So in your case I suggest you apply the Conditions->Accuracy (Custom) tool to the problem surfaces. Keep increasing the Accuracy: Custom->Resolution parameter until the element size on the surface allows a better shaped cell to bridge the small gaps. For more details see "Accuracy Tool".

Also while performing this, I suggest you don't have a live volume mesh (it will keep regenerating and slow you down) - so just look at Scalar Fields->E Ratio (surface cell quality measure, 0 = linear, 1 = perfect) on the surface. Once you are happy, then create VolRatio.