PDF] Ship roll control and energy harvesting using a U-tube anti-roll tank

Description

In the traditional design of passive anti-roll tanks (ART), the energy associated with the tank fluid motion is dissipated. The work reported in this paper explores the possibility that this energy is instead harvested. It is analytically determined in the paper how the natural frequency and the damping ratio of a U-tube ART should be tuned to maximise the power absorbed by the tank fluid. To this end, a perfectly flat spectrum of the moment representing the excitation of the ship by waves has been assumed. It is found that a tuning that maximises the power absorbed by the ART fluid motion also minimises the average kinetic energy of the ship roll. This is a result of the fact that the power input of the wave excitation moment into the ship plus tank system does not depend on how the ART is tuned. Therefore, different tunings of the ART natural frequency and damping ratio only affect the distribution of the power dissipated by the ship roll damping and the power absorbed by the ART.