Wingsail Camber-Adjusting Devices for Low-Stress Reefing
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Solution Overview
Problem
Conventional reefing systems for profiled sails, such as those described in WO 2021/148734A1, are unsuitable and can cause local stresses leading to tearing in strong winds, and there is a need for a system to adapt the sail area based on wind conditions.
Innovation Solution
A system comprising semi-rigid, elastically deformable cambering devices with actuating means that allow the sail to be hoisted, lowered, and adjusted to an intermediate position, using structural and secondary cambering devices to reduce the sail area by folding it along the mast, with a removable fixing system to manage excess sail sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If conventional reefing systems are used on profiled sails, then sail area can be reduced, but local stresses cause tearing in strong winds
Solution Approach 1:
The sail is divided into multiple panels that can be independently folded and stowed. Each panel is separated by creases and can be managed individually through the reefing system, allowing progressive reduction of sail area without concentrating stress on single attachment points
Solution Approach 2:
The reefing system uses dynamic folding mechanisms with creases that allow the sail to adapt its shape progressively. The sail transitions from a fully deployed state to partially stowed states through controlled folding motions, distributing mechanical stress across multiple flexible joints rather than rigid attachment points
2Adaptability or versatility
If sail area is reduced by folding onto the boom, then adaptation to wind conditions is achieved, but complex reefing procedures are required
Solution Approach 1:
The sail panels are pre-configured with creases and attachment points during manufacturing, establishing predetermined folding paths and stress distribution patterns. This preliminary structuring eliminates the need for complex manual folding procedures during reefing operations
Solution Approach 2:
The sail structure itself provides the reefing mechanism through its built-in creases and panel configurations. The sail folds and stows using its own structural properties rather than requiring external reefing gear, winches, or complex mechanical systems
3Productivity
If multiple cambering devices are used to control sail profile, then sail performance is improved, but device complexity increases
Solution Approach 1:
Each cambering device is designed to perform multiple functions: controlling the camber of individual sail panels, providing structural support for panel attachment, and serving as a pivot point for folding operations. This multi-functionality reduces the need for separate components for each function
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system effectively reduces sail area without causing local stresses, allowing adaptation to varying wind conditions and preventing tearing, while maintaining sail integrity.
Implementation Method 1
a semi-rigid, elastically deformable structure, including: -- two length sections, extending one in front of the other, respectively forming a first length section integral with a first surface of the profiled sail, and a second length section integral with a second surface of the profiled sail
Data Source
Figure 1
Figure 1a~3
Figure 4~5
AI summary
The present disclosure relates to an assembly comprising a wingsail, a mast and multiple camber-adjusting devices for a wingsail, the camber-adjusting devices comprising: - an elastically deformable semi-rigid structure comprising: -- two lengthwise sections, one extending ahead of the other, forming a first lengthwise section which is secured to a first area of the wingsail and a second lengthwise section which is secured to a second area of the wingsail, respectively; and -- a U-shaped connecting section extending from and connecting the first lengthwise section and the second lengthwise section. Said assembly comprises a system for reducing the area of the wingsail catching the wind, which system is configured to reduce the area of the wingsail comprising multiple wingsail sections (SV1 to SV5), and structural camber-adjusting devices (10 to 14).