Sailing Boat Mainmast with Adjustable Slats for Stall Prevention
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Solution Overview
Problem
Existing sailing boat designs face challenges in maintaining optimal aerodynamic performance of the mainmast, particularly in variable wind conditions, leading to potential stalling of the airfoil and reduced efficiency during high-speed sailing.
Innovation Solution
The mainmast is designed with a symmetrical, vertically extruded profile and adjustable orientation about its vertical axis, combined with slats on the upper portion to manage varying air flow angles and prevent stalling, while jibs enhance the aerodynamic lift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mainmast is designed with a fixed airfoil profile, then the manufacturing is simple, but the aerodynamic performance deteriorates in variable wind conditions due to stalling
Solution Approach 1:
The mainmast incorporates adjustable slats that can be positioned at different angles relative to the mainmast body, allowing the airfoil profile to be dynamically modified according to wind conditions. This dynamic adjustment prevents stalling by optimizing the angle of attack, thereby maintaining reliable aerodynamic performance without requiring a completely complex reconfigurable structure.
Solution Approach 2:
The invention changes the geometric parameters of the airfoil by adjusting the position and angle of the slats. By varying the angle between the slats and the mainmast body, the effective airfoil shape is modified to match different wind conditions, optimizing performance while keeping the base structure relatively simple.
2Force
If the mainmast angle is adjusted to maximize thrust force, then the forward propulsion is improved, but the airfoil stalls in gusty winds due to misalignment with free air flow
Solution Approach 1:
The slats are designed to be adjustable, allowing the mainmast to dynamically adapt its airfoil profile in response to changing wind conditions. When gusts occur, the slats can be repositioned to maintain optimal angle of attack, preventing stall while preserving thrust force generation capability.
Solution Approach 2:
The system implicitly uses feedback from wind conditions to adjust the slat positions. By monitoring apparent wind angle and intensity, the mainmast control system adjusts the slat angles to maintain optimal aerodynamic conditions, preventing stall while maximizing thrust.
3Productivity
If the mainmast is made rotatable about vertical axis to align with apparent wind, then the aerodynamic efficiency is improved, but the control complexity increases due to multiple adjustment mechanisms
Solution Approach 1:
The mainmast control system is segmented into independent adjustable elements (slats) that can be individually positioned. This segmentation allows each slat to be optimized independently for different wind conditions, achieving high sailing speed without requiring complete rotation of the entire mainmast, thus reducing overall control complexity.
Solution Approach 2:
Instead of making the entire mainmast rotatable, only specific local elements (the slats) are made adjustable. This local quality approach maintains the simplicity of the mainmast structure while providing the necessary aerodynamic adaptation capability through localized adjustments at the airfoil sections.
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 configuration extends the operating range of the airfoil, optimizing aerodynamic conditions and enhancing sailing performance by maintaining efficiency even in gusty winds and varying wind directions.
Implementation Method 1
the mainmast is defined by a symmetrical, vertically extruded profile, which often also has the ability to rotate about its vertical axis with respect to the deck of the hull, in order to try to align the front edge, or leading edge, of the airfoil defined by the mainmast with respect to the direction of the apparent wind
Implementation Method 2
the angle of incidence of the air flow towards the leading edge of the mainmast varies along the height of the mainmast. As mentioned above, this variation in the direction of the incident air flow is further amplified by the effects of the boundary layer of the Earth
Implementation Method 3
hydrodynamic lifting foils, or hydrofoils or even more simply foils, which are configured so as to have a hydrodynamic lift that is able to support the weight of the vessel and keep the hull out of the water when the vessel is sailing at relatively high speeds
Data Source
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AI summary
A mainmast (21) for a sailing boat (1) has a support base (S) and an upright (P), which extends along an axis from the support base (S) and defines an airfoil symmetrical with respect to an ideal median plane (M), with a leading edge (50) and two convex surfaces (21a,21b) that extend from the leading edge (50); the upright (P) can be oriented about its axis with respect to the support base (S), in order to position, in use, the leading edge (50) with respect to an incident air flow; the upright (P) has a lower portion (P1) and an upper portion (P2), which supports two slats (52a,52b), symmetrical to each other with respect to the ideal median plane (M), in positions spaced apart from the convex surfaces (21a,21b), respectively, so as to define respective slots.