A Dynamical System for the Combined Performance of Innovative Biomimetic Thruster With Standard Propulsion System in Waves

Abstract

Abstract Dynamic wings located at the bow of the ship are investigated for wave energy extraction from ship motions, augmenting ship propulsion in waves and improving dynamic stability in waves. In the context of Seatech H2020 project (https://seatech2020.eu/) flapping-foil thrusters and Dual Fuel engine technologies are combined to provide a renewable-energy-based hybrid solution for the reduction of fuel consumption and operational cost. At first stage of analysis a simplified approximation is developed exploiting data from systematic series for modelling ship propulsion in waves including ship motions and foil loads. In the present work a novel dynamical system is developed and applied to the combined performance of innovative biomimetic thruster in waves. The proposed method exploits seakeeping analysis and unsteady foil theory for the estimation of the ship-foil dynamic system coefficients and loads. The ship steadily advances in the presence of waves that are modelled by parametric spectra corresponding to specific sea states. Appropriate time integration techniques are used for the evolution of the system responses and foil loads. To examine the feasibility of the proposed propulsion innovation in short-sea shipping industry the case of a ferry ship is examined. Numerical results indicate that significant ship performance can be obtained under realistic operating conditions. Thus, the present method can serve as a useful tool for assessment and the preliminary design of such systems extracting energy from sea waves for the augmentation of ship propulsion.