Experimental Seakeeping Assessment of a Warped Planing Hull Model Series

One monohedral and three warped hard chine planing hull forms were designed at Department of Industrial Engineering, University of Naples. All models have the same transversal section at 0.25L from the stern with 16.7 degrees deadrise angle. Warped models have deadrise angle linearly varying along the hull length. In previous work the results of an extensive experimental program in calm water were presented. This paper is focused on the seakeeping assessment in regular waves. Aim of this research is the evaluation of the effect of deadrise angle variation along the hull length on seakeeping characteristics. Regular wave tests have been chosen to get better insight on motion and acceleration properties connected with warped hull forms and to provide a benchmark for CFD of planing hulls. Models with same load coefficient were tested at three volumetric Froude numbers FrV=1.92, 2.60 and 3.25. Reported results are nondimensional responses for heave, pitch, and accelerations at 0.5L and bow. Particular emphasis was given to acceleration analysis by crest to trough method and spectral analysis of first and second harmonics. All results are commented with respect to hull form variation. Uncertainty analysis has been performed according to ITTC 2011 recommendations.