The Representation of a Given Ship Form by Singularity Distributions When the Boundary Condition on the Free Surface is Linearized

The inaccuracy of the usual representations of an actual ship hull, that is of a hull neither thin, nor flat, nor slender, seems to be one of the main causes of the discrepancy between the measured and calculated values of the wave resistance. It is shown in the first part of this paper that a line singularity distribution should be associated with the surface singularity distribution over the hull. In the second part, the order of magnitude of the contribution of the line singularity is evaluated in the particular case of a vertical, elliptical, infinite cylinder. It is considerably high when normal doublet distribution is used. It becomes of the first order at low Froude numbers in the case of a source distribution. The problem still requires extensive research in several directions outlined at the end of the paper.