Acute-Angle Foil Structure for Watercraft Stability
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Solution Overview
Problem
Current watercraft designs face challenges with stability and efficiency in rough waters due to high water resistance and slamming effects, with hydrofoils experiencing cavitation issues and surface piercing catamarans having large wetted areas and instability.
Innovation Solution
A foil structure with elongated hull sections and protruding foils oriented at an acute angle, providing buoyancy and lift, and optionally featuring fins and water intake mechanisms, designed to reduce water resistance and enhance stability and efficiency by planing on the water surface and damping wave penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional hull designs are used, then the watercraft can float stably, but water resistance is high and speed is reduced
Solution Approach 1:
The hull is divided into two separate elongated hull sections that are positioned apart from each other, with foils protruding from each section. This segmentation allows each hull section to have reduced wetted area while maintaining overall stability through the distributed configuration of multiple lifting surfaces.
Solution Approach 2:
The invention transitions from a single-plane hull design to a three-dimensional configuration with foils protruding vertically from the hull sections. The foils are oriented at acute angles to the horizontal plane, creating lifting surfaces that operate in multiple dimensions to generate lift and reduce water resistance.
2Speed
If hydrofoils are used to reduce water resistance, then speed increases, but cavitation problems occur at maximum speeds
Solution Approach 1:
The foils have specifically designed local geometries with rounded leading edges and tapered sections that optimize flow characteristics. The foil cross-sections are shaped to prevent cavitation by maintaining smooth flow attachment and reducing pressure differential extremes that cause cavitation at high speeds.
3Speed
If surface piercing catamarans are used to decrease water resistance, then speed increases, but pitch instability occurs in rough water
Solution Approach 1:
The foils are oriented at acute angles to the horizontal plane rather than vertically, creating an asymmetric configuration that provides both lift generation and pitch stability. The angled orientation allows the foils to cut through waves at an optimal angle, reducing pitching moments while maintaining high-speed performance.
Solution Approach 2:
The invention combines the functions of hull sections and foils into an integrated system where the foils protrude from the hull sections and work together as a unified lifting and stabilizing system. This merging allows the structure to simultaneously generate lift, reduce water resistance, and provide pitch stability in rough water.
4Use of energy by moving object
If large wetted areas are used, then buoyancy is maintained, but water resistance increases and efficiency decreases
Solution Approach 1:
The foil structure provides dynamic lift that changes with watercraft speed and sea state. At higher speeds, the foils generate more lift to reduce wetted area and water resistance. The system adapts its effective wetted area dynamically rather than being fixed, optimizing the balance between buoyancy and water resistance across different operating conditions.
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 foil structure enhances stability and efficiency by reducing water resistance and fuel consumption, while being adaptable for various watercraft types, including retrofits, and improving landing and take-off capabilities for aircraft.
Implementation Method 1
A foil structure with elongated hull sections and protruding foils oriented at an acute angle, providing buoyancy and lift
Implementation Method 2
providing buoyancy and lift to a floating device
Implementation Method 3
designed to reduce water resistance and enhance stability and efficiency by planing on the water surface
Implementation Method 4
enhance stability and efficiency by planing on the water surface and damping wave penetration
Data Source
Figure 1a~1b
Figure 1c
Figure 1d
AI summary
A foil structure for providing buoyancy and lift to a floating device is provided. The foil structure comprises an elongated left hand side floating device section and an elongated right hand side floating device section. The left hand side floating device section and the right hand side floating device section are placed at a predetermined distance to a longitudinal axis of the floating device and oriented substantially parallel thereto. A left hand side foil and a right hand side foil protrudes from the left hand side floating device section and the right hand side floating device section, respectively, towards a vertical plane through the longitudinal axis and is oriented at an acute angle to a horizontal plane. A leading edge of each foil intersects the respective floating device section in proximity to a bow portion thereof. Each foil extends along the respective floating device section and terminates in proximity to a stern portion thereof. Each foil has a top surface with a front portion thereof being angled downward towards the leading edge. The angled front portion is determined such that wave penetration is assisted and instabilities due to buoyancy change are substantially dampened.