A multi-objective optimisation study of trimaran hull applying RBF-Morph technique and integrated optimisation platform at two design speeds

ABSTRACT

This paper presents an efficient optimisation method to improve the main hull of a trimaran ship, whilst proposing a computational fluid dynamics-based automated approach to reduce total resistance. A mesh-based method is introduced to modify a wave-piercing bow trimaran hull at two cruise and sprint speeds. Therefore, the problem pertains to a hydrodynamic multi-objective optimisation problem. Radial basis function-based mesh-morphing tool is implemented to alter the geometry at the mesh level. Mesh-morphing tool leads to elimination of geometry and mesh regeneration steps that consequently provides a shortcut for the designer's extrication from optimisation time and complexity of geometry modification. Ten global parameters accomplish expansion and contraction of the 10 sections, which are known as Magnification Factor. Optimisation results and design comparison illustrate the applicability and efficiency of the proposed technique. The results demonstrate 6.77% reduction in total resistance at cruise speed and 1.55% at sprint speed.

KEYWORDS:

• Trimaran hull
• optimisation
• total resistance
• CFD
• mesh morphing

Acknowledgment

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors and there is no conflict of interest.

Disclosure statement

No potential conflict of interest was reported by the author(s).