Solution 6.38
Just as in Prob. 6.37, apply the log-law at the center between the wall, that is, y = h/2, u = V/2.
With
w known, we can evaluate u* immediately:
15 /2 1 * /2
* 0.123 , ln ,
998 *
wm V u h
uB
su
= = = +
/2 1 0.123(0.03/2)
or: ln 5.0 23.3, .
0.123 0.41 0.001/998
VSolve for Ans
= + =
m
V 5.72 s