Dynamic Performance of the NTUA Double-Chine Series Hullforms in Regular Waves

Abstract

A systematic series of double-chine, wide-transom hull forms with warped planing surface has been developed at the Laboratory for Ship & Marine Hydrodynamics (LSMH) of the National Technical University of Athens (NTUA) during the last 15 years. The series, inspired by a proposal of Savitsky et al (1972), provides a handy and suitable base for the design of medium and large modern monohull ships and pleasure craft, which operate at high but pre-planing speeds. The series consists of five hull forms with L/B ratios equal to 4.00, 4.75, 5.50, 6.25 & 7.00. Two scaled models for each hull form have been constructed and tested at six displacements, including very light ones. The resistance characteristics of the series were presented by Grigoropoulos and Loukakis (2002). On the way to investigate systematically the dynamic performance of the series in waves, model tests have been carried out in regular waves and the results are presented in this paper. The tests encompass three level-keel displacements and two speeds corresponding to Fn = 0.34 and 0.68. The RAO curves for heave, pitch, acceleration at two points along the hull as well as added resistance are presented. Furthermore, the ambitious and time-consuming experimental investigation which is underway to test the hull forms of the series in sea states is described.