Active Stabilization Device for Watercraft Rolling Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active stabilization devices for watercraft, such as fin stabilizers, are inefficient in damping rolling movements when the watercraft is not moving or moving slowly, as they rely on varying the angle of attack to generate insufficient hydrodynamic forces, limiting their effectiveness and requiring larger stabilization surfaces.
Innovation Solution
The active stabilization device employs a positioning system that allows the stabilization surface to pivot and rotate simultaneously around a pivot axis and an axis of rotation, enabling complex spatial movements and increased damping efficiency with a reduced stabilization surface size, optimized for low-speed operations by adjusting the pivot and rotational angles and incorporating recesses and inflow bodies to minimize resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If fin stabilizers vary the angle of attack to generate hydrodynamic forces, then damping effect is improved, but stabilization surface area must be increased to achieve sufficient forces at low speeds
Solution Approach 1:
The stabilizing surface is made dynamically movable through the positioning device that enables both pivoting and rotating movements. This dynamic capability allows the surface to actively vary its angle of attack and generate sufficient hydrodynamic forces at low speeds without requiring a larger surface area, as the motion itself creates the necessary force multiplication effect
Solution Approach 2:
The positioning device implements periodic pivoting and rotating movements of the stabilizing surface through the water. This periodic action generates time-varying hydrodynamic forces that effectively dampen rolling movements at low speeds, allowing smaller surface areas to achieve the same stabilization effect that would require much larger static surfaces
2Force
If fin stabilizers are pivoted back and forth at constant angle of attack to build hydrodynamic forces, then damping effect is improved, but device complexity increases due to additional hydraulic actuators
Solution Approach 1:
The positioning device merges the pivoting movement and the rotation (angle of attack variation) into a single integrated mechanism controlled by one hydraulic actuator. This combination eliminates the need for separate actuators for each degree of freedom, reducing device complexity while still achieving the necessary complex spatial movements to generate effective hydrodynamic forces
Solution Approach 2:
The single hydraulic actuator in the positioning device performs multiple functions by simultaneously controlling both the pivot angle and the angle of attack of the stabilizing surface. This multi-functionality allows the system to achieve complex stabilization effects with fewer components, reducing overall device complexity while maintaining effective force generation
3Volume of stationary object
If stabilization surface size is reduced, then installation space is reduced, but damping effect decreases
Solution Approach 1:
The reduced stabilization surface is compensated by making it dynamically active through the positioning device. The surface undergoes coordinated pivoting and rotating movements that generate time-varying hydrodynamic forces, allowing a smaller surface area to produce sufficient damping force that would otherwise require a much larger static surface
Solution Approach 2:
The positioning device imparts periodic pivoting and rotating movements to the smaller stabilizing surface, creating oscillating hydrodynamic forces that effectively counteract rolling movements. This periodic action enables a compact surface to generate adequate damping force through motion-induced force multiplication
4Force
If angle of attack is varied to generate hydrodynamic forces, then damping effect is improved, but flow resistance increases
Solution Approach 1:
The positioning device implements periodic pivoting and rotating movements that create time-varying angles of attack. This periodic variation allows the stabilizing surface to generate effective hydrodynamic forces during the motion cycles while spending part of the time in lower-resistance configurations, reducing overall flow resistance compared to maintaining a constantly high angle of attack
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 approach achieves enhanced damping of rolling movements with a smaller stabilization surface, reducing installation space and flow resistance, and effectively counteracts rolling movements at speeds of zero to 4 knots, providing a superior stabilization effect.
Implementation Method 1
hydrodynamic forces caused by the stabilizing surface moving underwater
Data Source
Figure 1~1a
Figure 2~3
Figure 4~5
AI summary
The invention initially relates to an active stabilization device (10) for primarily damping rolling movements of a watercraft, in particular a ship (12), having at least one positioning device (18) with an output pin (20) and with a stabilization surface (16) fastened to the output pin (20) in the region of its root (22), wherein the stabilization surface (16) has a leading edge (40) and a trailing edge (42) and the stabilization surface (16) is arranged under water (26). According to the invention, it is provided that the stabilization surface (16) can be pivoted by means of the positioning device (18) about a pivot axis (S) by a pivot angle (β) and can simultaneously be rotated about a rotation axis (D) by means of the positioning device (18).Due to the suitably superimposed pivoting and rotational movements of the at least one stabilizing surface (16) of the stabilizing device (10), a particularly effective attenuation of the rolling movements of the watercraft is possible. Furthermore, the invention relates to a method for operating such a stabilizing device (10).