Ship Centerplane Source Distribution
A procedure for calculating the irrotational flow about a double ship model, by solving a Fredholm integral equation of the first kind for a centerplane source distribution, is described. The special problems of determining the curve in the centerplane bounding the source distribution and of smoothing sharply peaking inte-grands, to improve the accuracy of discretization of the integral equation, are treated. Application to ellipsoids, for which the results of the calculations can be compared with an exact solution, and to a ship form with parabolic lines, for which experimental data are available for comparison, indicate that satisfactory accuracy can be obtained by the method. A justification for using a centerplane distribution is that, as is shown, a line integral which appears in the higher-order solution for the flow about a ship form at nonzero Froude numbers can be avoided with such a distribution.