Nowaekt and Sharma 
The measured wave profiles were analysed by the Fourier 
transform method as explainedinAppendixB.8 and the results compared 
with the corresponding theoretical calculations based on explicit sour- 
ce representations of the hull and the propeller .The measured and cal- 
culated nondimensional free-wave amplitude spectrum E , and its sine, 
cosine components F , G are plotted as functions of nondimensional 
transverse wave number u in Fig . 17 to 19 for Y9 = 7.0 and in Fig. 20 
to 22 for Yy5 = 4.0. The following remarks are added to avoid any am- 
biguities of interpretation . The bare hull calculations are based on 
Equation (B 23), the propeller calculations on Equation (B 27) in con- 
junction with (B 16) , and the total system hull-propeller on Equation 
(B 30) . The free-wave spectra of the propeller alone in Fig. 19 and 
22 are referred to a coordinate system with its origin in the propeller 
plane , see Equation (B 73) , whereas all others refer to a coordinate 
system with its origin in the midship section of the hull (see Fig.1 ). 
Some obvious conclusions are in order here . First , the agree- 
ment between calculations and measurement is only qualitative at the 
lower speed , but quite good at the higher speed . Second , the discre- 
pancy between theory and experiment for the bare hull is mostly in 
phase and not so much in the amplitude of the free-wave spectrum . 
This is consistent with previous results of similar comparisons , see 
Sharma (1969) . Third , the fair agreement between the 'measured'" 
free-wave spectrum of the propeller - it was actually derived from the 
principle of linear superposition , see Equation (B 72) - and the calcu- 
lated spectrum shows that our theoretical model of propeller wavema- 
king is reasonable and that the pseudo-nonlinear effect of the propeller 
on the hull waves referred to above is at least not the predominant 
phenomenon . 
Finally , the calculated and measured wavemaking resistance 
according to Equations (B 28, 29) and (B 74) respectively are compared 
in the following table . 
Nondimensional coefficient Rg 2/ pve as calculated (measured) 
Speed-length parameter Yo= 7 or F,=0.267 You 4 or FK,=90.354 
Hull alone 0.0650 (0.0380) 0.0354 (0.0245) 
0.0037 (0.0039) 0.0013 (0.0037) 
0.0017 (0.0001) 0.0058 (0.0025) 
0.0704 (0.0420) 0.0425 (0.0307) 
Propeller alone 
Interaction term 
System hull and propeller 
1860 
