Wind Turbine Rotor Blade Winglet Segmentation

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Solution Overview

Problem

Existing rotor blades for wind turbines face a trade-off between aerodynamic and acoustic benefits from end plates, which increase friction and reduce energy yield due to higher surface area exposure.

Innovation Solution

The rotor blade design incorporates a closing element with multiple winglet pairs, where winglet longitudinal axes form specific angles relative to the rotor blade axis, reducing aerodynamic resistance and friction while maintaining aerodynamic and acoustic advantages, achieved through a smaller closing element area compared to traditional end plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an end plate is attached to the rotor blade tip, then aerodynamic conditions are improved and noise is reduced, but friction increases and energy yield decreases

Engineering Contradiction:
Improvenoise generationVSAvoidenergy yield
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The closing element is divided into multiple winglet pairs instead of using a single solid end plate. Each winglet pair consists of individual wings spaced apart, creating a segmented structure that reduces continuous surface friction while maintaining the vortex-reducing aerodynamic benefits at the blade tip

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The winglets are oriented at specific angles (α1 and β1 less than 180°, preferably around 90°) relative to the rotor blade longitudinal axis, introducing angular orientation in a new dimension. This angular arrangement allows the winglets to manage tip vortices effectively while presenting a smaller effective friction surface to the incoming wind compared to a traditional end plate

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If an end plate is attached to the rotor blade tip, then aerodynamic conditions are improved, but aerodynamic resistance increases

Engineering Contradiction:
ImproveturbulenceVSAvoidaerodynamic resistance
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The closing element is divided into multiple winglet pairs instead of using a single solid end plate. Each winglet pair consists of individual wings spaced apart, creating a segmented structure that reduces continuous surface friction while maintaining the vortex-reducing aerodynamic benefits at the blade tip

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The winglet pairs are configured with asymmetric orientation angles (α1 on the pressure surface side and β1 on the suction surface side, both less than 180°), creating an asymmetric structure that optimizes flow management while minimizing resistance to the incoming wind

Inventive Principle:
Principle #4Asymmetry

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 design optimizes energy yield by minimizing friction and noise generation, enhancing the aerodynamic properties and reducing turbulence, allowing for more efficient wind energy harvesting.

Implementation Method 1

an attached end plate leads to higher friction due to its surface facing away from the flow. This higher friction counteracts the positive effect of better buoyancy

Methodology Applied
Scientific EffectAerodynamic drag reduction: Drag

Implementation Method 2

better lift is achieved by the fact that vortices are reduced by the end disk at the end of a blade and instead of a flow detaching as a vortex, it is 'at the rotor blade'

Methodology Applied
Scientific EffectVortex reduction: Vortex Ring

Data Source

PatentEP2978967B1Rotor blade of a wind turbine having a winglet
Publication Date: 2019.10.16 ROHDEN ROLF
  • EP2978967B1 patent drawingFigure 1a~1b
  • EP2978967B1 patent drawingFigure 2~4
  • EP2978967B1 patent drawingFigure 5

AI summary

The invention relates to a rotor blade, in particular for a wind turbine, having a blade root, a blade tip, a pressure surface and a suction surface, wherein the pressure surface and the suction surface are connected to one another in an incident-flow region and the blade tip has a terminating element, in particular a winglet, wherein the terminating element has a first winglet vane and a second winglet vane, wherein a first winglet vane longitudinal axis has, at the pressure surface side, an angle α1 of less than 180° or less than 150° or less than 120° or less than 90° or less than 60° with respect to a first rotor blade longitudinal axis, and a second winglet vane longitudinal axis has, at the suction surface side, an angle β1 of less than 180° or less than 150° or less than 120° or less than 90° or less than 60° with respect to a second rotor blade longitudinal axis, such that the first winglet vane and the second winglet vane form a first winglet vane pair.