Exploring efficiency improvements in a transitional hull form

Abstract

This work looks at the potential to improve the efficiency of a powered monohull operating in the transitional speed zone between displacement and planing. It looks at the potential to make significant efficiency improvements through applying some of the conceptual characteristics of both modern performance yachts and fast displacement multihulls to influence the characteristics and hull form of a powered vessel. It also evaluates the characteristics and performance achievements of transitional hull forms developed for performance sail boats, in order to combine these with other characteristics found to be essential to efficiently extend the performance of these boats beyond displacement mode. With a focus on optimization in the transitional speed zone, a review of existing solutions to this problem are considered, including various hull forms, use of foils, and developments in mono and multihull performance yacht and powercraft design. This paper presents the development of a concept hull design that is influenced by performance yachts and multihulls, which is clearly reflected in its hull form and principal characteristics. To analyse this hypothesis the concept hull is developed and compared to more conventional monohull displacement and planing hull forms. Factors influencing performance such as appendage drag, displacement-length ratio and power to weight are compared and considered.