Numerical computations and integrations of the wave resistance Green's function

In order to develop an efficient method, using Kelvin-Havelock singularitie s, to compute the steady Lifting flow around a ship with forward speed, the accuracy of computations of Green's function and boundary integrations hav e been investigated. The computations have been done using interpolation fr om tables for the nonoscillatory term of Green's function and using series for the oscillatory one; it has been shown that a region exists, close to t he free-surface, where this last term must be computed by complete integrat ion to ensure a prescribed error. Three schemes of boundary integrations ha ve been studied; first boundary integrations have been performed using a Ga uss method. Then, to improve accuracy, Fourier and boundary integrations ha ve been interchanged either only for the oscillatory term or for both terms . Numerical results are compared and discussed taking into account both pre cision and computational time, for a submerged ellipsoid and for a lifting surface-piercing body.