Catamaran Fin Propulsion Between Parallel Floats
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Solution Overview
Problem
Existing catamaran fin drives face inefficiencies due to lateral water flow around the propulsion fin, which reduces propulsion efficiency.
Innovation Solution
A catamaran design with a drive fin that moves up and down between parallel floating bodies, ensuring the fin never extends below these bodies, thereby minimizing lateral flow and maximizing efficiency through a guide and drive mechanism that actively or passively pivots and deforms the fin within a maximum distance of 20 mm from the wall areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the drive fin extends beyond the floating bodies in vertical direction, then the working surface area is increased, but lateral water flow around the fin is generated reducing propulsion efficiency
Solution Approach 1:
The patent transitions from vertical extension of the fin (third dimension) to horizontal positioning between parallel wall sections (first dimension). The fin is moved up and down within the horizontal space between the floating bodies' wall sections, eliminating vertical protrusion while maintaining effective working surface area through optimized horizontal positioning and angle of attack.
Solution Approach 2:
The patent converts the harmful lateral water flow that would occur with vertical fin extension into a beneficial configuration by positioning the fin between parallel wall sections. This arrangement uses the wall sections to constrain and direct water flow, transforming what would be a loss into a controlled flow pattern that enhances propulsion efficiency.
2Loss of energy
If the drive fin is positioned between parallel wall sections of floating bodies, then lateral flow is prevented and propulsion efficiency is maximized, but the fin cannot extend vertically beyond the floating bodies
Solution Approach 1:
The patent relocates the fin's working surface from vertical extension to horizontal positioning between parallel wall sections. The fin achieves its full working surface area through optimized horizontal placement and angular orientation rather than vertical protrusion, effectively using the available horizontal space between the floating bodies.
Solution Approach 2:
The fin is designed to be movable up and down between the floating bodies through a guide and drive mechanism, allowing dynamic adjustment of its position and angle of attack. This dynamic capability enables the fin to optimize its interaction with water flow while remaining constrained within the horizontal boundaries set by the parallel wall sections.
3Loss of energy
If the fin is actively pivoted and deformed about a transverse axis, then propulsion efficiency is improved through optimized water interaction, but device complexity increases
Solution Approach 1:
The fin is equipped with a guide and drive mechanism that enables active pivoting about a transverse axis and deformation, allowing the fin to dynamically adjust its angle of attack and orientation. This dynamic capability optimizes the fin's interaction with water flow throughout its up-and-down movement cycle, maximizing propulsion efficiency.
Solution Approach 2:
The guide and drive mechanism is designed to enable the fin to pivot and deform in response to water flow conditions, allowing the system to self-optimize its propulsion characteristics. The mechanism facilitates passive deformation capabilities while maintaining active control when needed, reducing the need for complex external control systems.
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 enhances propulsion efficiency by preventing lateral flow around the drive fin, ensuring it lies completely between the floating bodies in all positions, thereby improving the overall efficiency of the fin drive mechanism.
Implementation Method 1
The propulsion fin 4 does not move downwards beyond the floats 2 and 3 and is thus protected by the floats 2 and 3 from collisions with the bottom of the respective body of water or other obstacles. The propulsion fin 4 is moved up and down below a water surface 23 to propel the catamaran 1
Implementation Method 2
the propulsion fin 4 is actively and/or passively pivoted and/or deformed about a transverse axis 22
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
A catamaran (1) has two floating bodies (2, 3) arranged transversely next to one another at a floating body spacing (5), a propulsion fin (4) extending transversely along the floating body spacing, and a guiding and driving mechanism (11) designed to move the propulsion fin up and down between the floating bodies, wherein the propulsion fin is actively and/or passively pivoted and/or deformed about a transverse axis. The propulsion fin extends between mutually parallel wall regions (6, 7) of the floating bodies and ends in at least one region of each of its two side edges (25), which region is moved up and down relative to the wall regions by the guiding and driving mechanism, within a maximum distance (8) of 20 mm from the wall regions.