Foam Stabilizer Fin Channel for Watercraft Stability

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Solution Overview

Problem

Existing boat designs face issues with stability and performance, particularly in rough waters, due to the use of inflatable cylinders which create drag and result in a poor ride, and prior art foam stabilization methods do not adequately address the need for both high-speed maneuverability and low-speed stability.

Innovation Solution

A planing hull watercraft with outboard stabilizing members featuring a fin on the bottom surface that forms a channel, providing hydrodynamic lift and pressurization to counteract heeling and improve ride quality, using D-shaped foam or cylindrical inflatable bladders mounted above the chine with a fin extending from the stabilizing member to create a channel between the hull and fin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If inflatable cylinders are used to form the sides of the boat, then stability is improved, but drag increases and performance deteriorates

Engineering Contradiction:
ImprovestabilityVSAvoiddrag
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The inflatable side is segmented into a upper cylindrical portion and a lower fin portion. The cylindrical portion provides stability while the fin portion is positioned to minimize drag during planing. This segmentation allows each part to perform its optimal function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fin portion extends downward from the cylindrical body into a different spatial dimension (below the water surface). This dimensional extension allows the fin to generate hydrodynamic lift and reduce drag without affecting the stability-providing cylindrical shape above water.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If inflatable cylinders are used as boat sides, then stability is improved, but ride quality deteriorates due to skipping and bouncing

Engineering Contradiction:
ImprovestabilityVSAvoidride quality
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The side structure is divided into a upper cylindrical portion for stability and a lower fin portion for ride quality. The fin portion interacts with water to provide hydrodynamic cushioning that reduces skipping and bouncing, while the cylindrical portion maintains stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inflatable cylindrical portion contains pressurized air that provides buoyancy and cushioning. This pneumatic element absorbs impacts and reduces the skipping and bouncing effect, improving ride quality while maintaining stability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Stability of the object's composition

If inflatable cylinders are used for boat sides, then stability is improved, but interior space is reduced

Engineering Contradiction:
ImprovestabilityVSAvoidinterior space
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

The side structure is segmented into an upper cylindrical portion that contains the interior space and a lower fin portion that provides hydrodynamic functions. This segmentation allows the interior volume to be maximized in the upper portion while the lower fin portion provides stability and drag reduction without encroaching on interior space.

Inventive Principle:
Principle #1Segmentation

4Stability of the object's composition

If inflatable cylinders are used as boat sides, then stability is improved, but reliability deteriorates due to damage from tears and leaks

Engineering Contradiction:
ImprovestabilityVSAvoiddamage resistance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The side structure is divided into an upper cylindrical portion and a lower fin portion made of different materials with different properties. The fin portion uses a damage-resistant material that is less susceptible to tears and leaks, while the cylindrical portion maintains the inflatable stability function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The side structure uses composite construction with the fin portion made from a rigid or semi-rigid material that is more resistant to damage from collisions and punctures. This composite approach allows the inflatable cylindrical portion to provide stability while the rigid fin portion provides damage resistance.

Inventive Principle:
Principle #40Composite materials

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 stability during low-speed maneuvers and provides a softer ride in rough waters by generating a lifting force that counteracts heeling and reduces the physical impact of waves, while maintaining high-speed performance and minimizing damage risk from collisions.

Implementation Method 1

a fin that extends from a lower surface of the stabilizing member to form a channel between the exposed portion of the sidewall and the fin. During certain operating conditions, a portion of the water displaced by the hull is directed toward the channel between the hull wall and the fin, thereby hydrodynamically pressurizing the channel, and generating a lifting force

Methodology Applied
Scientific EffectHydrodynamic lift: Aerofoil

Implementation Method 2

a portion of the water displaced by the hull is directed toward the channel between the hull wall and the fin, thereby hydrodynamically pressurizing the channel, and generating a lifting force

Methodology Applied
Scientific EffectHydrodynamic pressurization: Pressure Gradient

Data Source

PatentEP2027010B1Foam stabilized watercraft with finned collar
Publication Date: 2013.12.25 SAFE BOATS INTERNATIONAL LLC
  • EP2027010B1 patent drawingFigure 1~2
  • EP2027010B1 patent drawingFigure 3
  • EP2027010B1 patent drawingFigure 4~5

AI summary

A watercraft (100) is disclosed having a rigid hull (110) and outboard stabilizing members (112) attached to the hull sides (116). The hull preferably has a V-shaped bottom (118) and comprises a planing hull. The stabilizing members are preferably foam stabilizers, but may alternatively be inflatable bladder members. The stabilizing members cover a portion of the hull sides, extending part way to the chine (120) defined between the hull sides and the hull bottom. The stabilizing members each include an elongate fin (130) that extends from a bottom surface of the stabilizing member, and disposed in a front portion of the stabilizing member and in the region of the greatest hull dead rise angle. The fins may be formed integrally with the stabilizing members or may attach to the stabilizing members. The fins define a channel between the hull sides and the fins, that is hydrodynamically pressurized during certain watercraft operations, an in particular during low speed maneuvering.