[Liander]

Dear All,

I am meshing a 3D S-Duct through Icem and have used the strategy that you can see in the picture (basically everything, including the farfield, is meshed through a series of O-Grids that are contained within each other).

My problem is that while everything is fine when I try to generate the mesh with very high values for the boundary layer elements, as soon as I set an appropriate y+ value the mesh has orientation issues.

In the picture you can see the axialsymmetric cowl and,despite the blocking being symmetric, the apparently random distribution of volume inverted elements.

I have tried changing the boundary layer growth ratio, tried changing the block size and shape and tried varying number of elements along the defining curves (where if I decrease them in number, the issue seems to improve).

Does anyone know what causes the problem and how I can resolve it?

Thank you!