Nowaekt and Sharma 
Incidentally, ifthe source strength is uniform over the disk , as 
in Equation (B15) , the integral (B64) simplifies to 
byRwp = 44°(Rp* - Ry”) o (R) (w, + wy) (B68) 
where wp and w,, are the disk averages of the potential and wave 
wake respectively . Moreover , if only the potential component of 
thrust deduction is wanted , substituting from (B15) in (B68) and 
taking advantage of (B67) one obtains 
eee 
fa thea & Nibin Ne al get (B69) 
This is slightly different from the classical result of Dickmann (1939), 
cf. his equation (15) . However it agrees with Tsakonas' (1958) 
equation (12) , except that he does not distinguish between the poten- 
Pp and the total wake wp 
B.8. Wave Profile Analysis 
tial component w 
The purpose of wave profile analysis was to establish the true 
or experimental free-wave spectrum (and associated wavemaking 
resistance) of the hull and propeller as opposed to the theoretical 
spectrum based on linearized source representations discussed in the 
previous sections . The longitudinal cut method of Sharma (1966) as 
described in Eggers, Sharma and Ward (1967) was used. The essential 
steps of the analysis are given below. 
Let z =$ (x, yg) be a longitudinal cut through the wave pattern 
of the model as measured at a fixed transverse location y = y, in the 
coordinate system of Fig. 1 . Define modified * Fourier transforms 
C* (avg) iS te tepid) =f V2 -1 § (x, yo) exp(isx) dx (B70) 
* The asymptotic nature of the wave pattern behind a ship is such 
x/|y (—-» seo : (x,y) ~ exp(ix)/ «/c-x 
that the modified Fourier transform remains finite for any s , while 
the ordinary Fourier transform becomes infinite at s=1. 
1904 
