Federico Alzamora Previtali

Hello Eric, 

It will generally be more accurate to resolve the viscous sublayer with a finer grid (y+ ~1), especially for cases involving flow separation or heat transfer. However, for simple flow geometries with attached flow, you can still get accurate results with proper wall treatment.

What the wall treatment does is that it will blend between viscous sublayer formulation and law of the wall formulation based on the local y+ value. How this is achieved will vary between different turbulence models but is general for all wall treatment methods.