Wind Turbine Blade Appendix with Duct for Flow Stabilization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wind turbine aerodynamic rotor blade appendices are large, heavy, and expensive, failing to efficiently utilize wind energy and prevent aerodynamic stall, particularly in the blade root region.

Innovation Solution

A lightweight, compact aerodynamic appendix with a cylindrical inner portion and airfoil outer portion, featuring a duct connecting the pressure and suction sides, and optionally including vortex generators and adjustable flaps, to stabilize flow and enhance lift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large aerodynamic appendix is used to increase wind turbine efficiency, then the useful surface area and energy conversion capacity are improved, but the weight, cost, and structural complexity increase significantly

Engineering Contradiction:

Improvewind turbine efficiencyVSAvoidappendix weight

Core Design Contradiction:

ProductivityVSWeight of moving object

Solution Approach 1:

The aerodynamic appendix is divided into multiple functional segments: a cylindrical inner portion attached to the blade root, an intermediate transition portion, and an outer airfoil portion. This segmentation allows each part to be optimized independently for its specific function while reducing overall material requirements compared to a monolithic large appendix structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the appendix have different cross-sectional geometries optimized for their local aerodynamic requirements. The inner cylindrical portion provides structural attachment, the intermediate portion provides gradual transition, and the outer airfoil portion maximizes energy extraction. This local optimization allows the appendix to be lightweight while maintaining high efficiency.

Inventive Principle:

Principle #3Local quality

2Weight of moving object

If a thin and lightweight aerodynamic appendix is used, then the cost and ease of handling are improved, but the flow stability and lift generation capacity deteriorate

Engineering Contradiction:

Improveappendix weightVSAvoidflow stability

Core Design Contradiction:

Weight of moving objectVSReliability

Solution Approach 1:

The intermediate portion acts as an aerodynamic intermediary that gradually transitions the flow from the cylindrical inner portion to the airfoil outer portion. This gradual transition prevents flow separation and maintains stable, attached flow across the entire appendix structure, enabling lightweight design without sacrificing flow stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The appendix employs curved and streamlined geometries throughout, particularly in the intermediate transition portion and the airfoil contours. These smooth curved surfaces promote attached flow and reduce turbulence, maintaining flow stability even in the lightweight thin-section design.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Strength

If the inner and intermediate portions of the blade are used for energy extraction, then the structural resistance is improved, but the wind energy conversion capacity in these regions is wasted

Engineering Contradiction:

Improvestructural resistanceVSAvoidwind energy conversion

Core Design Contradiction:

StrengthVSProductivity

Solution Approach 1:

The aerodynamic appendix transforms the inner and intermediate blade portions from single-function structural elements into multi-functional components. These portions now serve both their original structural support function and a new aerodynamic energy extraction function, eliminating waste and improving overall system efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The appendix design allows the blade to dynamically utilize wind energy across its entire span. By adding aerodynamic surfaces to the inner and intermediate portions, the system adapts to extract energy from wind impinging on these previously non-productive regions, maximizing energy conversion while maintaining structural integrity.

Inventive Principle:

Principle #15Dynamics

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 solution increases wind turbine efficiency by stabilizing flow and increasing lift, while being cost-effective and easy to assemble, effectively utilizing otherwise underexploited wind energy near the hub.

Implementation Method 1

at least one duct connecting the further pressure side fluidically to the further suction side

Methodology Applied

Scientific EffectFluid flow:

Implementation Method 2

The aerodynamic appendix preferably comprises at least one vortex generator inside the duct. The vortex generator stabilizes flow along the further suction side.

Methodology Applied

Scientific EffectVortex generator: Vortex Generator

Implementation Method 3

the aerodynamic appendix... comprises a further trailing edge, a further pressure side, a further suction side

Methodology Applied

Scientific EffectAerodynamic lift: Aerofoil

Data Source

PatentEP2917569B1Wind turbine aerodynamic rotor blade appendix and wind turbine blade provided with such an aerodynamic appendix

Publication Date: 2016.10.19 WINDFIN BV

Figure 1
Figure 2~3
Figure 4~5

AI summary

An aerodynamic appendix (8) for a wind turbine blade (7) is designed to fit to the inner portion (12) and intermediate portion (13) of the wind turbine blade (7), and has a trailing edge (19), a pressure side (20), a suction side (21), and at least one duct (14) connecting the pressure side (20) fluidically to the suction side (21).