Bidirectional Vortex Energy Extraction via Wake Galloping

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Solution Overview

Problem

Conventional vortex-induced vibration energy extraction devices are limited to operating with tidal currents flowing in one direction, failing to efficiently utilize mechanical energy from both flood and ebb tides, and require additional devices to adapt to flow direction changes, increasing manufacturing and maintenance costs.

Innovation Solution

A vortex-induced vibration energy extraction device with a pair of vibrating bodies coupled to a support body on the seabed, where one body generates energy through direct vortex-induced vibration and the other through wake galloping, allowing energy extraction in both flood and ebb tide directions without the need for additional direction change devices, and featuring a parked condition maintaining mechanism to control the vibrating body's angle and shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional vortex-induced vibration energy extraction devices are used, then energy can be extracted from unidirectional flow, but the device cannot efficiently utilize mechanical energy from bidirectional tidal currents (flood and ebb tides)

Engineering Contradiction:
Improveadaptability to flow directionVSAvoidenergy extraction efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The device employs asymmetric configuration of vibrating bodies positioned at specific locations (front and rear) relative to the support body. This asymmetric arrangement allows the front vibrating body to generate vortex-induced vibration while the rear vibrating body utilizes wake galloping from the vortex shed by the front body, enabling effective energy extraction from bidirectional tidal currents without requiring additional direction-changing mechanisms

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The vibrating bodies are designed to dynamically respond to flow direction changes through their coupling mechanisms (first and second coupling mechanisms) that allow rotational movement. This dynamic capability enables the device to automatically adapt to flood and ebb tide directions, maintaining energy extraction efficiency across varying flow conditions without mechanical intervention

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If additional devices are added to adapt to flow direction changes, then bidirectional energy extraction becomes possible, but manufacturing and maintenance costs increase

Engineering Contradiction:
Improveadaptability to flow directionVSAvoiddevice structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The vibrating bodies serve multiple functions simultaneously: they generate vortex-induced vibration when positioned at the front, and they utilize wake galloping when positioned at the rear. This multi-functionality eliminates the need for separate direction-changing devices, reducing structural complexity while maintaining adaptability to bidirectional flows

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The device utilizes the vortex generated by the front vibrating body to drive the rear vibrating body through wake galloping. This self-service mechanism allows the system to automatically exploit bidirectional flow energy without requiring external control systems or additional mechanical components, thereby simplifying the overall device structure

Inventive Principle:
Principle #25Self-service

3Productivity

If vibrating bodies are positioned to maximize energy extraction, then power generation efficiency improves, but the device cannot operate during repair or emergency conditions

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidmaintenance accessibility
Core Design Contradiction:
ProductivityVSEase of repair

Solution Approach 1:

The device is segmented into modular components including the support body, first vibrating body, and second vibrating body, each coupled through independent coupling mechanisms. This segmentation allows individual components to be easily accessed, removed, or replaced during maintenance operations without affecting the entire system, thereby improving ease of repair while maintaining operational efficiency during normal conditions

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

Enables adaptive energy extraction in bidirectional tidal currents or ocean currents, improving power generation efficiency and reducing manufacturing and maintenance costs by allowing simultaneous vortex-induced vibrations in both flow directions and minimizing vibration during repair or emergencies.

Implementation Method 1

the vibrating body positioned upstream in the flow direction, with regard to the flow direction of the fluid, is configured to generate mechanical energy through vortex-induced vibration resulting from the flow of the upstream fluid

Methodology Applied
Scientific EffectVortex-induced vibration: Kármán Vortex Street

Implementation Method 2

the vibrating body positioned downstream in the flow direction is configured to generate mechanical energy through wake galloping caused by a vortex generated behind the vibrating body positioned upstream

Methodology Applied
Scientific EffectWake galloping: Kármán Vortex Street

Implementation Method 3

an energy conversion device provided on the support body so as to convert mechanical energy resulting from vortex-inducted vibration of the vibrating bodies due to the flow of the fluid to electric energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3657011B1Vortex-induced vibration energy extraction apparatus
Publication Date: 2022.09.07 KOREA INSTITUTE OF OCEAN SCIENCE & TECHNOLOGY
  • EP3657011B1 patent drawingFigure 1
  • EP3657011B1 patent drawingFigure 2
  • EP3657011B1 patent drawingFigure 3

AI summary

Disclosed is a vortex-induced vibration energy extraction device. The vortex-induced vibration energy extraction device according to the present disclosure is configured to extract electric energy from mechanical energy caused by vortex-induced vibration of a vibrating body. Multiple vibrating bodies are configured and installed on both sides of the support body, respectively. The one-side vibrating body is configured to generate mechanical energy through vortex-induced vibration by means of a fluid flowing in one direction. The opposite-side vibrating body is configured to generate mechanical energy through vortex-induced vibration by means of a fluid flowing in the opposite direction. When the vibrating body positioned upstream in the flow direction, with regard to the flow direction of the fluid, generates mechanical energy through vortex-induced vibration resulting from the flow of the upstream fluid, the vibrating body positioned downstream is configured to generate mechanical energy through wake galloping caused by a vortex generated behind the vibrating body positioned upstream. The present disclosure is advantageous in that the vortex-induced vibration energy extraction device installed offshore can extract energy through vortex-induced vibration resulting from both flood tide and ebb tide, the energy extraction efficiency can be improved by wake galloping, and energy can be extracted adaptively in connection with tidal currents or ocean currents moving in various directions.