Crescent Vortex Elements for Wind Turbine Blade Flow Control

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Solution Overview

Problem

Conventional vortex generators on wind turbine blades increase drag and noise, and are less effective near the blade root where flow separation is more prevalent, limiting lift generation and energy conversion efficiency.

Innovation Solution

The design of unique aerodynamic vortex elements with an upwardly inclined wind face and downwardly inclined slip face, resembling crescent sand dunes, are placed on the blade surfaces to create turbulent airflow and delay flow separation, reducing drag and noise while enhancing lift, particularly near the blade root.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional vortex generators (fins or shaped structures) are added to the blade surface, then flow separation is prolonged and aerodynamic airflow is optimized, but drag increases and noise increases

Engineering Contradiction:
Improveflow attachmentVSAvoiddrag and noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent employs curved, sand-dune-inspired vortex elements with rounded leading edges and trailing edges, replacing conventional flat or fin-type vortex generators. This curvature allows the vortex elements to generate effective turbulence and delay flow separation while reducing drag and noise through smoother airflow transition.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent modifies the geometric parameters of the vortex generators by adopting a specific curved profile resembling crescent sand dunes, with particular attention to the radius of curvature at the leading edge and trailing edge. These parameter changes optimize the vortex generation capability while minimizing harmful effects such as drag and noise.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional vortex generators are placed near the blade root, then flow separation is addressed in the region where it is most prevalent, but the lift generation is limited due to the increased drag and noise

Engineering Contradiction:
Improveflow attachment near blade rootVSAvoidlift generation
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The curved sand-dune profile of the vortex elements enables them to function effectively near the blade root by generating turbulence that delays flow separation, while the reduced drag and noise allow the blade to maintain higher lift generation capability in this critical region.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

By optimizing the geometric parameters of the vortex elements to match the curved sand dune form, the patent achieves effective flow control near the blade root without the penalties of increased drag and noise, thereby preserving lift generation productivity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the attached-flow region is increased by moving flow separation nearer the trailing edge, then energy conversion efficiency increases, but this requires specific aerodynamic modifications that increase device complexity

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidaerodynamic modifications
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies vortex elements as discrete, segmented structures distributed along the blade surface rather than using complex continuous modifications. This segmentation approach achieves the desired flow control and increased attached-flow region while keeping the overall device complexity manageable through modular, repeatable elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent achieves improved energy conversion efficiency by optimizing the parameters of the vortex elements (curved profile, size, spacing) rather than implementing complex aerodynamic modifications. This parameter optimization approach provides effective flow control with minimal increase in device complexity.

Inventive Principle:
Principle #35Parameter changes

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 vortex elements effectively increase lift and reduce drag, improving energy conversion efficiency by extending the attached-flow region and minimizing the detached-flow region, especially near the blade root, without significantly increasing resistance or noise.

Implementation Method 1

create turbulent airflow and delay flow separation

Methodology Applied
Scientific EffectTurbulent airflow: Turbulence

Implementation Method 2

delay flow separation, reducing drag and noise while enhancing lift

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Implementation Method 3

increase lift and reduce drag, improving energy conversion efficiency

Methodology Applied
Scientific EffectAerodynamic lift: Aerofoil

Implementation Method 4

creating a pressure difference between the top and bottom surfaces of the blade

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP2400148B1Wind turbine blades with aerodynamic vortex elements
Publication Date: 2015.08.12 GENERAL ELECTRIC CO
  • EP2400148B1 patent drawingFigure 1
  • EP2400148B1 patent drawingFigure 2~3
  • EP2400148B1 patent drawingFigure 4~5

AI summary

A wind turbine blade (16) has a suction side surface (20) and a pressure side surface 922). A plurality of vortex elements (34) are formed on at least one of the suction side or the pressure side surfaces. The vortex elements (34) have a semi-hemispherical crescent shape with a concave wind face (40) and a convex slip face (44), with the wind face and slip face meeting at an arc-shaped ridge (42).