Optimization of upwind sailing applying a canting rudder device

Abstract

The research explained in this paper was carried out to investigate the efficiency of different steering systems on sailing yachts. The steering system of a sailing yacht mostly includes a simple steering system and a hydrodynamic shaped single rudder, or multiple rudders, depending on boat characteristics. One of the basic design guidelines for fast sailing yachts involves reducing the wetted surface to the minimum allowed by the dynamic stability while maintaining the optimal sailing performances. Deficiencies of different steering systems are discussed and their influences on total lift and yaw moments; yacht manoeuvrability in different sailing directions is also analysed. The discussion is focused on steering systems applicable in practice and accepted by the yacht-building industry, although several innovations may be found that remained in their development stage because of their complexity in construction, maintenance, use itself and reliability. The canting rudder is analysed applying an uncommon approach for ship building. All measurements have been conducted at sea applying on board sensors for position and acceleration acquirements. The purpose of the research is to demonstrate that the use of the bended rudder can reduce the leeway angle, the upwind sailing angle and increase the velocity made good to windward.