Fuel savings for a general cargo ship employing retractable bow foils

Abstract

Route simulations were performed on a 100 m long (between perpendiculars) general cargo ship equipped with retractable bow-mounted foils, so-called wavefoils, for resistance reduction and motion damping in waves. Two round-trip routes were simulated: Orkney Islands to Iceland and across the Bay of Biscay. Ship motions and added resistance in waves were calculated in the frequency domain. Foil thrust was calculated in the time domain, based on a frequencydomain model of the vessel motions with wavefoils, using a slightly modified version of the Leishman-Beddoes dynamic stall model (Leishman and Beddoes, 1989). For both directions of each route, 1000 journeys with and without wavefoils were simulated, with wind and wave conditions obtained from ECMWF hindcast data. In the simulations, two identical ships, one equipped with wavefoils and the other without, were assumed operating in parallel, starting their journeys at random times between January 1, 2000, and December 1, 2014. The brake power was constant for the ship without wavefoils, whereas the ship with wavefoils reduced its power to obtain the same speed as the ship without wavefoils. For the most favorable route with respect to this study, Orkney Islands to Iceland, the average fuel saving was 22% for a constant brake power without foils that corresponds to a calm-water speed of 14 knots.

Operational sea passage scenario generation for virtual testing of ships using an optimization for simulation approach

“…Sandvik et al [6] present a simulation-based methodology for investigating ship design susceptibility towards operational delays during marine operations limited by the occurrence of operable weather windows. Bøckmann et al [7] evaluate the fuel saving potential of retractable bow foils by simulating 1000 voyages for two routes in the North Atlantic. In these studies, the understanding of the system's ability to function in its operating environment is evaluated using long-term statistics of system factors.…”

A Study of Multi-Component Oscillating-Foil Hydrokinetic Turbines with a GPU-Accelerated Boundary Element Method

“…As a result, these devices have gained popularity as secondary propulsion systems. References [5][6][7][8][9][10][11][12][13] provide detailed analysis of the characteristics of such systems. Also, some of the present authors were involved in the research project BIO-PROPSHIP [14] for the investigation of flapping foils.…”

Hydrodynamic analysis of ship and marine biomimetic systems in waves using GPGPU programming

“…Moreover, an extensive literature review on wave-powered USVs can be found in the aforementioned reference. More recently, Bøckmann et al (2018) estimated the fuel savings for a general cargo ship employing retractable bow foils. They observed that fuel savings were shown to decrease when installed power increases but remain at significant level when the ship advances at full speed.…”

“…Figure 1.9: The case vessel with wavefoils deployed from work Bøckmann et al (2018) were fuel savings from the wave-foils were estimated. ntua.gr/biopropship), is focused on the hydrodynamic analysis of flapping wings located beneath the ship's hull, operating in random motion; see Fig.…”

“…. .1.9 The case vessel with wavefoils deployed from workBøckmann et al (2018) were fuel savings from the wave-foils were estimated. .…”