John Laufer (NACA Tech Rep. 1174, 1954) gave velocity data 20°C airflow in a smooth 24.7-cm-diameter
The centerline velocity uCL was 30.5 m/s. Determine
(a) the average velocity by numerical integration and
(b) the wall shear stress from the log law approximation.
Compare with the Moody chart and with Eq. (6.43).