Reply To: Three-dimensional turbulent rough flows – y+ calculation

[Rob]

We're alittle restricted in what we (as Ansys staff) can comment on, so I can't give a full answer. 

In your case the channel is very small, so surface roughness may be big relative to the channel size: there's published data on micro channel shape issues but more so with laser & acid etching (well more that additive wasn't sensitive enough to consider using when I last looked into it). So, if you try and resolve down to y+ of around 1 you're resolving to the level where you may want to consider including the roughness in the geometry. However.... y+ is also a function used for turbulent boundary layers: is your system really turbulent?