Retractable Ship Stabilizer Fin With Dynamic Hatch
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Solution Overview
Problem
Existing retractable stabilizer fin systems for ships suffer from increased hydrodynamic resistance due to structural recesses in the hull, which occur whether the fins are extended or retracted, leading to higher fuel consumption and drag, as they disrupt the water flow and create vorticity phenomena.
Innovation Solution
A stabilizing device with retractable fins that features a holding compartment and hatches to minimize hydrodynamic resistance by maintaining the hull's continuity, with hatches that close to restore the bottom's shape when the fin is extended or retracted, using a connecting body and linear actuator to rotate the fin and hatches, ensuring uninterrupted water flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If retractable stabilizer fins are used, then the stabilizing effect is maintained, but hydrodynamic resistance increases due to structural recesses
Solution Approach 1:
The hatch is designed to dynamically change its configuration between open and closed states based on the fin position. When the fin is retracted, the hatch closes to restore hull continuity; when the fin is extended, the hatch opens to allow fin movement. This dynamic adaptation eliminates the need for permanent recesses, thereby reducing hydrodynamic resistance while maintaining stabilizing functionality.
Solution Approach 2:
The invention changes the parameter of hull continuity by introducing a movable hatch that can transition between open and closed positions. This parameter change allows the hull to maintain its streamlined shape during normal operation (reducing drag) while still accommodating the stabilizer fin when needed. The hatch's ability to change the effective shape of the hull eliminates the permanent drag-increasing recesses.
2Adaptability or versatility
If structural recesses are created for fin retraction, then fin retraction is enabled, but fuel consumption increases due to increased drag
Solution Approach 1:
The invention extracts the hatch from the permanent hull structure, making it a separate, movable component. This extracted hatch can be closed when not in use, eliminating the need for permanent recesses in the hull. By removing the permanent structural modification (recess), the hull maintains its optimal hydrodynamic shape, thereby reducing drag and fuel consumption while still enabling fin retraction capability.
Solution Approach 2:
The movable hatch changes the effective volume and shape parameters of the hull only when needed for fin retraction. When closed, the hatch restores the hull's original streamlined parameters, minimizing drag and fuel consumption. The temporary opening of the hatch during fin retraction does not create permanent drag-increasing features.
3Object-affected harmful factors
If hatches are closed to reduce drag when fin is retracted, then hydrodynamic flow is improved, but fin operation becomes more complex
Solution Approach 1:
The invention merges the hatch operation with the fin movement operation. The same actuator system that moves the fin also controls the hatch opening and closing. This combined operation reduces the number of independent mechanisms needed, simplifying the overall system despite the added hatch component. The coordinated movement ensures the hatch is open only when the fin is moving and closed when the fin is stationary.
Solution Approach 2:
The hatch opens in advance before the fin movement begins and closes after the fin movement is complete. This preliminary action ensures that the fin has clear access to move in and out of the hull without obstruction, while minimizing the time the hatch is open and thus minimizing the impact on hydrodynamic flow. The timing coordination between hatch and fin movement simplifies control logic.
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 significantly reduces hydrodynamic resistance at all fin positions, minimizing fuel consumption and drag, while maintaining the structural integrity and compactness of the device, even in harsh marine conditions.
Implementation Method 1
A stabilizing device with retractable fins that features a holding compartment and hatches to minimize hydrodynamic resistance by maintaining the hull's continuity
Implementation Method 2
hatches that close to restore the bottom's shape when the fin is extended or retracted, using a connecting body and linear actuator to rotate the fin and hatches, ensuring uninterrupted water flow
Data Source
AI summary
A retractable stabilizing device (1) for stabilizing a ship having a hull (2) defined by a bottom (3) having an opening (31, 32), said stabilizing device (1) comprising: a stabilizer fin (10); a connecting body (20) suitable to connect said stabilizer fin (10) to the hull (2), said connecting body (20) supporting said fin (10)., said connecting body (20) being rotatable together with said fin (10) with respect to the hull (2) between an extended position of said fin (10) so that said fin (10) projects from said hull (2) through said opening (31, 32) in said bottom, and a retracted position of said fin (10) so that said fin (10) goes completely back into said hull (3) through said opening (31, 32); a first closing hatch (62) integrally secured to the connecting body (20), said first hatch (62) being suitable to at least partially close said opening (31, 32) when the fin (10) is in said extended position, said first hatch (62) being shaped with an outer surface thereof suitable to restore the shape and continuity of the bottom (3) when said fin (10) is in said extended position.