Turbulence intensity dependent from the Re-Number
 

Hi everyone,

I have simulated an airflow in a rectangular pipe using k-epsilon model with wall functions enabled (y+ is ok). The Reynolds-Number for the flow is about 13000, thus it has to be turbulent. But being a newbie I have no idea what intensity of turbulence should I get for the fully developed pipe flow with this Re-number. 10%, 30%, 50%? Does anybody have a clue or a reference?

And the same but another question :). Starting from which value of turbulent intensity of a flow it is considered to be turbulent?

Did you try looking in Viscous Fluid Flow textbooks? You can try to match the boundary layer thicker. Also since the configuration seems like a benchmark case, you might find some experimental studies on the same.