[chikko04]

hi to all,
i re open this old thread, because of i didn't want to open another. I want to sim a channel dns, now i have some theoric questions:

1) why the density have to be equal 1?
2) what is the link between mass flow rate, reynolds bulk and reynolds nominal?
My second question is related to find out the right Reynolds tau to verify my y + into the mesh.

I apologize if these questions are basic, but i am a noob, and want understand what i do.