TR No. 22 
where c} is a dimensionless constant and A, B, and C are to be determined. 
Substituting the preceding dimensions into this equation, we obtain 
= ase Cc 
cm?y4 unten 28 = ML, 
from which 
NS al 
) 
B=0 
7 
@ Ss ih (26) 
y 
so that 
G. 8 el (27) 
2 a “ 
From equations (23) and (24), we get 
Assuming that I, L and C4 have the same values in air and in water, 
J air ( air = DM eecess ( water. (28) 
Therefore 
air -3 
)] water = /lair alg aly o2 ALO) ) air. 
(oes (29) 
The virtual moments of inertia in air and in water have been neglected in 
the foregoing analysis. 
The current meter was mounted in the test section of a closed circuit, 
single return, low speed wind tunnel (figures A-land A-2). A step function 
change in air velocity was simulated by suspending a small section of screen 
A-6 
