Profile Sail Boom with Hinged Sections for Airflow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sail booms disrupt the airflow and create vortices due to their rigid structure, leading to power losses and reduced propulsion efficiency, especially in the transition zones from the upper sail to the boom, where the airflow is not optimally deflected, resulting in increased sail pressure and heel.
Innovation Solution
A horizontally flexible profile sail boom with a T-shaped cross-section, featuring a vertically rigid central spar and angled transverse webs that guide airflow, preventing pressure equalization and reducing induced towing vortices, while adjustable tension cords and hard metal tilting bearings ensure optimal deflection and bending stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional rigid boom is used, then structural strength is maintained, but airflow is disrupted and vortices are created leading to power losses
Solution Approach 1:
The boom is divided into multiple hinged sections that can independently adjust their orientation. This segmentation allows each section to adapt to the airflow pattern while maintaining overall structural integrity, reducing vortex formation at transition zones between sail sections and the boom.
Solution Approach 2:
The boom transitions from a rigid structure to a dynamically adjustable one with hinged sections that can change orientation in response to airflow conditions. This dynamic adaptation allows the boom to align with the downwash flow from the headsail, minimizing harmful vortices and maximizing propulsive power.
2Ease of manufacture
If the boom is made straight and rigid, then manufacturing simplicity is achieved, but transition zones from upper sail to boom create airflow disruption and increased heeling
Solution Approach 1:
The boom is segmented into multiple hinged sections that can independently adjust, replacing a single rigid structure. This segmentation enables the boom to create smooth transition zones that guide airflow effectively, reducing heeling and maintaining ease of manufacture through modular construction.
Solution Approach 2:
The boom's geometric parameters (orientation angles of individual sections) are changed dynamically to optimize airflow guidance. By adjusting the orientation of each hinged section, the boom creates favorable transition zones that reduce harmful effects while maintaining structural simplicity.
3Power
If a profiled boom is used to match sail shape, then aerodynamic efficiency is improved, but device complexity increases with multiple segments and control mechanisms
Solution Approach 1:
The boom uses simple hinged sections that naturally align with airflow patterns, creating an effective profile without complex control mechanisms. Each section independently adapts to the flow, achieving aerodynamic efficiency through passive segmentation rather than active control systems.
Solution Approach 2:
The hinged sections of the boom automatically align themselves with the downwash flow from the headsail through aerodynamic forces, without requiring external control systems. This self-adjusting mechanism achieves optimal aerodynamic efficiency while minimizing device complexity.
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
The solution enhances propulsive power by up to a few percent with reduced heeling pressure, particularly on close-hauled courses, and improves overall sail efficiency by aligning airflow deflection with the sail's profile, maximizing downwash energy from the headsail.
Implementation Method 1
The lower crosspiece, on the one hand, limits or controls the horizontal buckling of the sections relative to one another. On the other hand, with its guide surfaces on both sides, it creates the aerodynamic resistance to largely prevent undesirable pressure equalization from the upwind to the opposite leeward side of the sail foot
Implementation Method 2
with its guide surfaces on both sides, it creates the aerodynamic resistance to largely prevent undesirable pressure equalization
Implementation Method 3
The required sail profile is determined by the deflection of the trimmable boom, extending all the way down to the bottom, which is automatically generated by wind pressure
Implementation Method 4
The resulting wake vortex and the vortex losses from the straight boom, which is not adapted to the current direction, detract from propulsion energy and should be prevented as far as possible
Implementation Method 5
The required sail profile is determined by the deflection of the trimmable boom, extending all the way down to the bottom, which is automatically generated by wind pressure
Data Source
Figure 1~2
Figure 3~6
Figure 7~8
AI summary
The invention relates to a profiled sail boom (1) for a boat, Said profiled sail boom (1) comprises a batten mainsail, is flexible in the horizontal direction, and has a vertical spar (21) with cords laminated in at the uppermost and lowermost points in the center of the cross-section, transverse webs (22) separated by wedge-shaped spacer joints (52) extending from said spar (21) in the horizontal direction at the lowermost point, wherein guiding tubes (49) for cords (50) are provided on the outer edges of said transverse webs (22), as depicted in Fig. 9.