turbulent flow velocity profiles

suvernfraggle

i've been given this question by my lecturer at university and im struggling with where to start with it to be honest. it feels like i don't have enough information. please can someone help?

For turbulent flow, the velocity profile inside a duct and a pipe of diameters Dd and Dp and
both with distance y from the centre line is: vy/vy=0 = (1-y/r)1/7, where vy=0 = vmean/0.817 and vmean=Q/A. Plot the velocity profiles for:

(a) Air flowing in a duct measuring Dd = 0.6m and with Re = 105.
(b) Water flowing in a pipe measuring Dp = 0.5m and with Re = 105.
(c) Calculate the vmean and vy=0 for both cases (a) and (b)
(d) If the Blasius equation f = 0.079Re-0.25 applies, calculate the values of f and ΔP/L for (a)

cloa513

http://en.wikipedia.org/wiki/Reynolds_number

You have to find the kinematic viscoscity from your textbooks or online.

You have enough. Assume hydrauilic diameter is the the same as actual diameter.