[delplatl]

hello,

I am working on fluid dynamic simulations of an agitated vessel with two impellers, a Rushton turbine and a pitch blade turbine.
I am using the workbench mesher. My geometry is divided in two zones, a moving mesh around the two impellers and a stationary mesh in all the rest of the domain.
I am having difficulties with the mesh generation, I have generated grids with maximum skewness of 0.801 and I did also the automatic mesh improvement in fluent, but I still have problems of convergence.
I am using tetrahedral grids, and I obtained it doing local elements sizing of the different mesh zones. I did two cylindrical cut around the two impellers and I generated a very refined mesh, then the moving zone is made of elements a little bigger and the stationary zone around the moving mesh is even coarser.
The stationary mesh at the top of the moving zone it has been automatically generated with hexahedral cells.
Do you have any other suggestion about the meshing strategy? Should I try to reduce the skewness to avoid convergence problems?
I attached two images of my geometry and mesh.
Thank you in advance