Reply To: Volumetric mesh with cell volumes smaller than machine precision

[Rob]

Fluent should be OK with that scale (we run micro fluidic models) but check the near wall resolution and aspect ratio too. 

Hybrid meshes should be fine, and were routine up until we moved to poly meshes for many applications. However, check the cell size change at the boundary between the cell zones as the pyramid caps can cause issues. 

As an aside, the length unit is metre.... ;)