Reply To: Boundary layer and y+ value

[Rob]

I'd start with some reading, not least to understand why you may want a different turbulence model. The meshing tutorials may also be of some use. Wall functions may well be covered in the Turbulence lecture in Learning (left tool bar on here). 

Depending on the size of the nozzle, and wider domain you may easily find the mesh exceeds 1M cells. That's fairly normal, but does conflict with the Student cell count limits.