Design and validation of a non-linear passive-selective compliant hydrofoil using shape-memory alloys

Abstract

Traditionally, sailboats relied on the Archimedes principle to move on the water surface. This method has been used and successfully proven for many thousands of years, with the earliest known depiction found on an Egyptian clay and dating from 3100 B.C. Nowadays, boats can fly by the means of hydrofoils, allowing great performance and efficiency when moving on the water surface. While hydrofoils are efficient in a defined spectrum because of their fixed geometry, this work presents a solution to increase the efficiency in a larger range of operation by proposing a non-linear compliant structure solution based on a AClass sailing catamaran. The objective of this work is to provide a proof of concept of a structure capable of adapting its geometry depending on the load case to which it is submitted to maximize the righting moment and the lift to drag ratio in different sailing conditions. To comply with the A Class rules, this geometrical change must be done passively. To begin, the load case validation and evaluation is performed for the boat take-off and maximum speeds using a custom designed hydrofoil geometry. The thesis then presents the developed tools and Finite Element Model allowing to determine analytically the performance of the Hydrofoil and its morphing and structural capabilities combining traditional CFRP composites and Shape Memory Alloys (SMA). As a final step, the validation of the morphing concept calculations on a 1:1 scale specimen to determine the real-case application and integration constraints is presented. Finally, an example of a full-cycle calculation process for an AClass catamaran with a morphing Hydrofoil is presented, to achieve a preliminary design concept.

Date	30 Oct 2017
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Simon Joncas (Supervisor) & Patrick Terriault (Co-supervisor)