Evaluation of trimaran bow shapes in head seas towing tank tests and results

Abstract

The future of naval architecture looks at improved ship designs which can operate in extreme weather while capable of achieving missions either commercial or naval. This demand for new and improved capabilities stipulates for research in this area. The concept of wave piercing bows for trimaran ships was investigated at UCL in the past, and this study aims to supply further information to past research regarding seakeeping behaviour. The contribution of two different wave piercing bow shapes, in terms of sea keeping for a wellknown trimaran destroyer design produced in the past by UCL, is assessed through tank model testing for an available range of frequencies and wave amplitudes. Due to limited facilities and time, the report only analyses heave and pitch motions in head seas. Essentially, the focus is directed towards assessing the impact of a wall-sided and a flared bow shape on trimaran performances, following any changes in heave and pitch equations of motion that they generate (such as differences in damping and stiffness). Finally, the project also describes the whole procedure from model design, model manufacture, model testing, to the understanding and presentation of any valuable findings.

Keywords

• trimaran, head seas, towing tank experimental tests