Empirical deep-water heave added-mass and radiation-damping expressions for 2-D rectangular-sectioned floating bodies

Two-dimensional added-mass and radiation damping data of Vugts (1968) related to heaving rectangular sections in deep water are represented by empirical formulas. Although other data exist, the Vugts data are considered to be the standard in experimental planar-motion hydrodynamics research of basic geometries of many floating bodies, including those of several wave energy conversion systems. The present empirical effort was undertaken to make the Vugts results useful in strip-theory analyses of the heaving and pitching motions of slender vessels having rectangular sections. For approximate predictions of the hydrodynamic coefficients (added-mass and radiation damping) of these systems, the empirical expressions provide manageable analytical expressions. In the derivations, the behaviors of the parametric constants for each coefficient are found to be approximate rectilinear functions of the beam-to-draft ratio. The applicability of the empirical expressions is enhanced by this finding.