Y+ Wall Distance Estimation
The formulas used are give in CFD-Wiki here
The Schlichting skin-friction formula, as desribed here
(equation 21.16 footnote in Schlichting), is used to estimate the local skin-friction for a turbulent boundary layer on a smooth flat plate. The correlation is valid for Re < 10^9. The density and viscosity given by default in the form is for air at sea-level and room temperature (20°C).