2023 Volume 79 Issue 17 Article ID: 23-17121
The use of simple rectangular flume-type anti-oscillation tanks to reduce the motion of a floating caisson during towing is investigated. In this study, the effect of anti-oscillation tanks on the motion of the caisson in irregular waves is investigated through a large scale hydraulic experiment at 1/15 scale and two types of numerical analysis: frequency response analysis and time series analysis. The pitch of the caisson was significantly affected by nonlinear damping during resonance at the natural period. It was found that the motion of the caisson in irregular waves is affected by nonlinear damping and frequency nonlinearity. The anti-oscillation tanks have the effect of damping the caisson pitch and changing the natural period. The effect is determined by the magnitude of the fluid force in the tanks and the phase difference between the fluid force and the pitch. The time series analysis generally reproduced the amount of motion of the caisson in irregular waves and the effect of the anti-oscillation tanks.
