Resistance assessment of warped hullform

Abstract

A series of hard chine planing hull forms was developed at Department of Naval Architecture, University of Naples. Three warped and one monohedral hulls were designed and four 6 ft long models were built. The models have the same transversal section at 0.25L from the stern with 16.7 degrees deadrise angle. Warped models had deadrise angle linearly varying along the hull length.Aim of the experimental program is the evaluation of the effect of deadrise angle variation along the hull length on hydrodynamic resistance and on seakeeping although this work presents calm water performances only.The models have clear polycarbonate bottom to allow flow visualization and accurate wetted surface assessment.Resistance tests were performed for speed coefficient CV ranging from 0.56 to 3.92 and for two load coefficient values: CΔ=0.428 and 0.392. Reported results are wetted lengths of pressure area and whisker spray area, projected angles of stagnation line, wetted surface and whisker spray area, residual resistance coefficient, sinkage, presented in standard non-dimensional form, and running trim.