Dagan 
2 
Zz 
ae (30) 
2 
D5 = -16e72/F 
(1 + 2e 
The wave resitance (30), of a blunt semi-infinite body in our 
approximation (fig. 2a), is represented in fig. 2c. We have ooo there 
the more common drag coefficient Cp = D' Jo GF Te ee) oF" 
With Cy = Cy, fe (Cpst+ Cys) wehavesy Co, =D, (2 
Cpp = D> _/ F2 _. We have also taken in this case L'=h', i.e. 
h=1, F* =U'*/gh' and €=T'/h'. 
On the same fig. 2c we have represented the coefficient of 
wave resistance for a semi-infinite body having a fine leading edge 
of a wedge shape (fig. 2b), created by distributing ten sources of 
equal strength at constant spacing. This way we could estimate the 
influence of the fineness of the bow on the nonlinear wave resistance. 
In fig. 2c we have represented Cp), as well as the ratios Ge /ay 
and Cys /Cp4 . The first ratio is a measure of the relative impor- 
tance of the free surface correction versus the body correction. The 
second ratio represents the relative magnitude of the second order 
correction. 
In these examples there are no interference effects because 
the bodies are of semi-infinite length. The next case considered was 
of a closed body generated by a source and a sink of equal strength 
(fig. 3a and 4a). With n=2 and e€,=-€5=2 in (28) and (29) we 
obtain in this case 
2 
Des =o [ty -ye08 (2° / F*)] 
Ds = - (ecb/FS lise. y Aen = Zc, + K, 5) sin(2/F°) + 
e (Caml? tepals oe) [1-cos(2 /F°)]} (31) 
where all the coefficients are given by (20) and (24). 
Again, we have represented the wave resistance in figs. 3 
and 4 in terms of the more conupon egret Cp = Di /2eU' Lis 
D./2E° Hence with Cp = e Cy, + € Ae: p2. ~we have this time 
Cy =D, /2E" and Gy'=D, /2F° *yin tie Be cde 
1706 
