Nowaekt and Sharma 
and the difference 
Rwr - Rw - Rywp = = if {GH (u) Gp (a) + Fy (a) Fp (u)| — du 
0 
(B32) 
is a measure of the interference between the wave patterns of the hull 
and the propeller . The interaction term can be positive or negative 
B.5. Wave Flow due to Hull 
The perturbation flow induced at the propeller plane by the 
motion of the hull under the free surface can also be calculated by 
thin ship theory . We start with the Green's function of the problem as 
defined by Equation (63) of Eggers , Sharma and Ward (1967 ): 
1 1 
Gi (sis) aie Wie = IS r] +> Ep 
2! ee a Ai 2 
eee hs [ex [-w |x-x"| tiu(y-y')+iY¥w -u"(z+z')] ay 
= 90 |u| ne -u2 -iw2 
J 
4s 
+im— + -sgn(2x-x')b {=z exp {is(-x") + iu(y-y') +s*(z+z') \ du 
with (B33) 
ry ae Pe oe (y-y')" + (ee 
+ (yay!) + (zt2t)* 
This is the velocity potential due to a point source of unit strength at 
(x', y', z') . Integration over the hull source distribution (B6) yields 
the velocity potential of the hull ¢ (x,y,z) , and subsequent differen- 
tiation with respect to x,y,z yields the components of perturbation 
velocity yx , Cyn Og It is convenient to break up each expres- 
sion into four parts corresponding to the four terms of the Green's 
function (B33) . For instance 
¢, (x,y,z) = e{1) + e) - e (3) .? (4) 
(B34) 
1894 
