Seakeeping Computations Using the Ship Motion Green's Function

摘要

We present a sea-keeping boundary elemen method of computation. The diffraction-radiation with forward speed Green's function in the frequency domain with an analysis of the accuracy and computational time needed for the boundary integration is used. The results of an analytical surface integration of Green's function and of its first and second derivatives are compared with a numerical procedure based on a Gauss method and further optimisations dependent on the relative location of the source and field points and to their distances to the free-surface. The results are compared for a single panel and a field point in the whole domain. This domain is divided in various zones in which different techniques of integration are used. These surface integration techniques are introduced in a panel method for sea-keeping computations adapted to the case of surface-piercing bodies or ships in forced oscillations. The results are also compared with results available from other calculation methods or from test measurements for the DNV barge or a simple surface-piercing flat plate.