Active Stabilizing Device for Watercraft Rolling Damping
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Solution Overview
Problem
Existing active stabilizing devices for watercraft, such as ships, face inefficiencies when not moving through water, as the leading edge of stabilizing fins experiences increased flow resistance due to water inflow in one direction and outflow in the opposite, leading to reduced energetic efficiency.
Innovation Solution
A stabilizing device with a pivotable and rotatable stabilizing surface, where the leading edge is always oriented against the water flow, and a non-co-rotating inflow body is used to optimize flow properties, allowing the surface to rotate 180° to maintain efficient hydrodynamic profiles and reduce resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the stabilizing fin is periodically pivoted back and forth in opposite directions, then the stabilizing function is achieved, but the trailing edge is exposed to water inflow causing significantly increased flow resistance that impairs energetic efficiency
Solution Approach 1:
The stabilizing surface is made rotatable about an axis of rotation in addition to pivoting about a pivot axis. This dynamic addition allows the leading edge to be continuously oriented against the water flow direction, transforming the static fin configuration into a dynamically adaptive one that maintains hydrodynamic efficiency throughout the stabilization cycle.
Solution Approach 2:
The stabilizing surface is rotated in advance about the axis of rotation so that the leading edge is positioned to face the incoming water flow before the pivoting action occurs. This preliminary orientation ensures that water always flows over the leading edge rather than the trailing edge, preventing the formation of high resistance flow patterns.
2Use of energy by moving object
If the stabilizing surface is rotatable about an axis of rotation, then the leading edge can always face the water flow reducing flow resistance, but the device complexity increases
Solution Approach 1:
The positioning device is designed to integrate both pivoting and rotation functions into a single coordinated system. The drive journal and associated actuators simultaneously control the stabilizing surface's pivoting about the pivot axis and rotation about the axis of rotation, merging two degrees of freedom into one unified positioning mechanism rather than requiring separate systems.
3Force
If the stabilizing surface is pivoted about a pivot axis, then the angle of attack can be changed to counteract rolling movement, but the trailing edge experiences water inflow causing increased flow resistance
Solution Approach 1:
By adding the rotation degree of freedom about the axis of rotation, the system dynamically adjusts the orientation of the stabilizing surface to maintain favorable flow conditions. The leading edge is continuously presented to the incoming water, while the trailing edge remains in the wake region, preventing the harmful flow resistance that would otherwise occur during pivoting operations.
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 significantly reduces flow resistance and energy demand, enhancing the energetic efficiency of the stabilizing device by ensuring the leading edge consistently faces the water flow, even when the watercraft is not moving, thereby improving the damping of rolling movements.
Implementation Method 1
the stabilizing surface includes a leading edge and a trailing edge, and the stabilizing surface is disposed under water... the leading edge is always flowed-against by the water... the lifting effect generated by the at least one wing-shaped stabilisation element will effect a damping of the ship's motion
Implementation Method 2
it is necessary, for example, to move the fin stabilizers back and forth through the water using further actuators at sufficient speed... to build up the hydrodynamic forces required for weakening the undesirable rolling movements
Data Source
Figure 1~3
Figure 4~6
AI summary
The invention first relates to an active stabilizing device (10) for primary damping of rolling movements of a watercraft including a hull (14), in particular of a ship (12), wherein the stabilizing device (10) includes at least one positioning device (18) including a drive journal (20) and including a stabilizing surface (16) attached to the drive journal (20) in the region of its root (22), wherein the stabilizing surface (16) includes a leading edge (40) and a trailing edge (42), and the stabilizing surface (16) is disposed under water (26). According to the invention it is provided that the stabilizing surface (16) having an angle of attack (y) set by the positioning device (16) is pivotable about a pivot axis (S) between a first and second position (80, 86) and is rotatable by the positioning device (18) about an axis of rotation (D). Consequently the leading edge (40) can always be oriented essentially in the direction of the pivot direction (82, 90) of the stabilizing surface (16), which stabilizing surface (16) is moving under water (26), which results in a considerable reduction of the flow resistance. A particularly energy-saving operation of the stabilizing device (10) is thereby possible. Furthermore the invention involves a method for operating the active stabilizing device (10).