Tiltable Flettner Rotary Rig for Bridge Clearance and Stability

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Solution Overview

Problem

Flettner-type rotating sails face challenges such as height limitations for passing under bridges, increased fuel consumption in headwinds, stability issues in strong winds, and complex maneuverability due to weight and drive systems, making them difficult to adapt to large ships.

Innovation Solution

A Flettner-type rotating rig with a lower and upper aerodynamic section connected by disconnectable means and a pivot joint, allowing the upper section to tilt relative to the lower section, reducing the overall height and weight, and incorporating a rotational balancing device for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the Flettner rotating rig is made taller to increase propulsion efficiency, then the sail thrust force is improved, but the ability to pass under bridges and fit in port facilities deteriorates

Engineering Contradiction:
Improvesail thrust forceVSAvoidability to pass under bridges
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The rotating rig is divided into two separate sections: a lower section that remains fixed on the ship and an upper section that can be tilted independently. This segmentation allows the upper section to be angled backward to reduce its vertical projection height, enabling the rig to pass under bridges while maintaining sufficient height for effective propulsion when in the vertical position.

Inventive Principle:
Principle #1Segmentation

2Force

If the Flettner rotating rig size is increased to improve propulsion performance, then the windage and thrust are improved, but the impact on ship stability in strong winds and fuel consumption worsens

Engineering Contradiction:
ImprovethrustVSAvoidship stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The rig transitions from a static vertical structure to a dynamic system where the upper section can change its angle relative to the lower section. This dynamic capability allows the rig to be tilted backward to reduce windage and its impact on ship stability when sailing in strong winds or headwinds, while maintaining full vertical height for optimal thrust generation when conditions are favorable.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the Flettner rotating rig is made lighter to facilitate tilting operations, then the ease of operation is improved, but the structural strength and rigidity deteriorate

Engineering Contradiction:
Improveease of tiltingVSAvoidstructural rigidity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

By separating the rig into lower and upper sections, the upper section can be designed to be lighter and easier to tilt, while the lower section contains the heavy drive means and provides the main structural support. This segmentation allows the upper section to achieve ease of operation for tilting maneuvers while the overall structure maintains sufficient strength through the robust lower section.

Inventive Principle:
Principle #1Segmentation

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

Facilitates maneuverability and reduces height, weight, and complexity of Flettner rotating rigs, enhancing their adaptability to various maritime conditions and ship designs.

Implementation Method 1

Flettner-type rotating sails, using the Magnus effect, are interesting because they allow the generation of sail thrust force

Methodology Applied
Scientific EffectMagnus effect: Magnus Effect

Implementation Method 2

tilting means comprising a pivot joint about an axis in a direction secant to the vertical direction, between the lower section and the upper section

Methodology Applied
Scientific EffectHinge mechanism: Hinge

Data Source

PatentEP4568884B1Tiltable flettner-type rotary rig
Publication Date: 2025.12.03 FARWIND ENERGY
  • EP4568884B1 patent drawingFigure 1
  • EP4568884B1 patent drawingFigure 2
  • EP4568884B1 patent drawingFigure 3

AI summary

The invention relates to a Flettner rotary rig (100) extending in a vertical direction about an axis of rotation (110), comprising: a lower section (101) comprising a lower aerodynamic surface (121) connected to a rotary drive means; an upper section (102) comprising an upper aerodynamic surface (122) connected to the lower aerodynamic surface (121) in continuity with same by releasable connection means (125, 321, 322); and tilting means (250) comprising a pivot connection (150), able to pivot about an axis directed secant to the vertical direction, between the lower section (101) and the upper section (102) at a height h (15) measured from the base (30), these tilting means being configured such that when the releasable connection means (125, 321, 322) are disconnected, the upper section (102) is able to pivot about the pivot connection (150) relative to the lower section (101).