by the computation with Equation (32). However, there still exist some 

 discrepancies when the Froude number is greater than 0.20. 



In order to achieve further improvement, some kind of revision of the 

 formula is desirable. We have employed the double body source distribution 

 in the expression of Equation (42), but it does not satisfy the hull sur- 

 face boundary condition at finite Froude numbers. Therefore, we try to 

 employ the source distribution by which the hull surface boundary 

 condition is satisfied at the Froude number under consideration. If we 

 assume that the line distribution along the water line and the distribution 

 over the horizontal plane do not make serious effects on the hull surface 

 boundary condition, the density of the source distribution over S is 

 determined by the integral equation 



IS. 



(Q) "gf- G(P,Q) d S Q (43) 



A numerical method is available to determine the source density c(P) . 

 Then the result is substituted in the formula, Equation (42), to calculate 

 the generalized Kochin function, which determines the wave resistance by 

 the formula, Equation (28). A numerical example is given for the case of 

 y = 6.0 or Fn = 0.2887. Three kinds of calculations are compared in 

 Figure 4. The first is the calculation by the ordinary Kochin function of 

 the distribution of sources on S only, i.e., only the first term on the 

 right-hand side of Equation (42) is taken. The second is the addition of 

 the line integral, which corresponds with the result of the Neumann- 

 Kelvin solution suggested by Brard. The third example is the inclusion of 

 all terms of Equation (42). Much closer agreement with measured results 

 are obtained by the addition of the third term of Equation (42). Recently 

 Kitazawa et al., presented another approximation. They put the density 

 of hull surface sources as 



a(P) = a Q (P) + a^P) (44) 



and determined O- (P) by the integral equation 



23 



