Session: 08-02-02 Ship & Floating Systems

Paper Number: 103284

103284 - Numerical Simulation of Motion Responses of a Cabin-Suspended Catamaran in Head Waves 

A suspension ship differs from a conventional rigid-body ship by having a suspension unit mounted between the cabin and the hull. Such a design allows the motion of the cabin to be separated from the hull, and therefore provides the potential to employ a control system to reduce the motion of the cabin and consequently improve ride comfort.

A model ship with 9 degree-of-freedom has been built and experimentally investigated. The proposed suspension unit allowed the relative heave, pitch, and row between the cabin and the hull to be produced, while restricting the relative surge, sway, and yaw motions. Towing tank experiments have been conducted in head waves at several motion control modes. However, due to the limitation on time and budget, the investigation of the motion response of the suspension ship was only carried out at a few wave frequency conditions.

To gain a thorough understanding of the motion response characteristics of the suspension ship, provide sufficient information for control system design, and explore the potential usage of suspension ships, studies on the interaction between the motion responses of the cabin and the hull, the desired control force, and the wave field have become essential.

In this study, a simulation program of the suspension ship built through the platform of OrcaFlex was presented. The numerical results of the motion responses of the suspension ship at different damping coefficients and spring stiffness were demonstrated, and the accuracy was verified with the experimental results. The motion interaction of the cabin and the hull with the variation of the control forces were discussed.

Presenting Author: Jialin Han Yokohama National University

Presenting Author Biography: Jialin Han is an assistant professor in the Department of Systems Design for Ocean-Space at Yokohama National University, Japan. Her research interests include R&D of suspension ships and wave energy converters.

Authors:

Jialin Han Yokohama National University
Daisuke Kitazawa The University of Tokyo
Motohiko Murai Yokohama National University