Vertical Plane Oscillation Experiments on a Series of Two-Dimensional SWATH (Small Waterplane Area Twin Hull) Demi-Hull Sections

摘要

Results of vertical plane oscillation experiments, conducted to determine the added mass and damping characteristics of a series of two-dimensional demi-hull sections are presented. These sections represent variants of several Small Waterplane Area Twin Hull (SWATH) ship designs currently in development, including a fully offset strut, commonly referred to as the golf club. Added mass and damping coefficient, along with radiated wave measurements, are presented for eight models, at two drafts and at least two amplitudes of oscillation. Comparisons between models illustrate the effects of lower hull geometry, strut offset, and strut thickness. Measured radiated wave data agree qualitatively with measured damping results, and are particulary interesting for the golf club hull forms where the radiated wave heights are asymmetric. Also presented are results of limited zero speed experiments on four models consisting of 3-D extensions added to the 2-D models. The coefficients are presented in the 2-D non-dimensionalization scheme, for comparative purposes. The results should provide information useful in the development and validation of SWATH seakeeping prediction programs for a range of hull forms. Keywords: Two dimensional added mass; Damping; Seakeeping. (jhd)