Dynamic modeling of ships towed by kite

Nedeleg Bigi,Christian Jochum,Kostia Roncin,Jean-Baptiste Leroux,Morgann Behrel,Alain Neme,Yves Parlier

doi:10.1051/lhb/2018002

Abstract

A dynamic kite flight can affect ship motions. Ship equations of motion associated with the analytical zero-mass kite model are developed. Aiming a realistic amplitude modeling of the kite excitation, a linear modification of the aerodynamic kite specs with the turning rate of the kite velocity heading is proposed. A good agreement with experimental data is obtained. Equations of motion are solved on a reaching path alternatively with a weak and a strong coupling between the ship and the kite. Differences between the two coupling methods become significant when a harmonic of the kite excitation approaches the natural roll frequency of the ship. For the presented case of study, these critical conditions can be avoided with longer tethers or larger kite trajectories.

Highlights

This work takes place within the beyond the sea® research program which aims to develop kites as an auxiliary propulsion device of ships for fuel saving
Dynamic simulations of a ship towed by kite were performed by Bigi et al [2017]
A strong coupling is performed into the time domain with a ship model based on the impulse response function [Cummins, 1962], the STF strip theory [Salvesen et al, 1970] and a zero-mass kite model [Leloup et al, 2016]

Summary

Dynamic modeling of ships towed by kite

Nedeleg BIGI 1, Morgann BEHREL 1, Kostia RONCIN 1, Jean-Baptiste LEROUX 1 Alain NEME 1, Christian JOCHUM 1, Yves PARLIER 2. Ship equations of motion associated with the analytical zero-mass kite model are developed. Le vol dynamique de cerf-volant peut modifier les mouvements d’un navire. Ainsi les équations du mouvement avec un modèle cinématique de cerf-volant sont développées. Les équations du mouvement sont résolues avec un couplage fort et un couplage faible entre le kite et le navire. Ces conditions sont à éviter car le navire est alors animé de mouvements de grandes amplitudes. Mots-clés : cerf-volant, navire, simulation dynamique, simulation temporelle, tenue à la mer, roulis, analyse fréquentielle, couplage fort, couplage faible

INTRODUCTION

The Laplace transform of H can be expressed as

Effects of this correction technique are presented in Figure