Rotor Blade Leading-Edge Mass for Aeroelastic Flutter Suppression

Solution Overview

Problem

As wind turbine size and rotor blade length increase, aeroelastic instabilities become more likely, leading to structural damage and increased costs due to unstable modes like flutter, which existing solutions address with additional mass, increasing fatigue loading and complexity.

Innovation Solution

A leading-edge corrective mass is positioned in the outboard region of the rotor blade to shift the center of mass towards the leading edge, creating favorable flap-torsion coupling and increasing aerodynamic damping, suppressing unstable aeroelastic modes without significant material addition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional mass is added to the rotor blade body to achieve positive damping, then aeroelastic stability is improved, but the mass moment and fatigue loading increase

Engineering Contradiction:

Improveaeroelastic stabilityVSAvoidmass moment

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies local quality by concentrating additional mass specifically at the leading edge of the rotor blade, rather than uniformly throughout the blade body. This localized mass placement provides the necessary aerodynamic damping and positive stability margin while minimizing the overall mass moment and its associated fatigue loading effects.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces a new spatial dimension for mass placement by positioning corrective mass at the leading edge, which is a different location than conventional blade body additions. This dimensional change in mass distribution optimizes the aerodynamic properties and stability characteristics without proportionally increasing the mass moment.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If additional mass is added to the outboard rotor blade region to suppress aeroelastic modes, then stability is improved, but edgewise fatigue loading increases

Engineering Contradiction:

Improveaeroelastic stabilityVSAvoidedgewise fatigue loading

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent applies local quality by concentrating additional mass specifically at the leading edge of the rotor blade, rather than uniformly throughout the blade body. This localized mass placement provides the necessary aerodynamic damping and positive stability margin while minimizing the overall mass moment and its associated fatigue loading effects.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The leading edge corrective mass acts as a counterweight that offsets the harmful aerodynamic forces causing flutter and unstable modes. By strategically placing mass at the leading edge, the patent creates a balancing effect that suppresses aeroelastic instabilities without proportionally increasing the mass moment and associated fatigue loading.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

3Reliability

If corrective mass is added to shift the center of mass towards the leading edge, then aerodynamic damping is increased, but device complexity increases

Engineering Contradiction:

Improveaerodynamic dampingVSAvoidmass placement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by concentrating additional mass specifically at the leading edge of the rotor blade, rather than uniformly throughout the blade body. This localized mass placement provides the necessary aerodynamic damping and positive stability margin while minimizing the overall mass moment and its associated fatigue loading effects.

Inventive Principle:

Principle #3Local quality

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 design suppresses unstable aeroelastic modes, allowing the wind turbine to operate at higher speeds and power outputs, reducing fatigue and structural damage, and avoiding revenue loss from curtailment, while maintaining stability with minimal additional material.

Implementation Method 1

The leading-edge corrective mass is adapted to shift the center of mass of that spanwise section towards the leading edge

Methodology Applied

Scientific EffectCenter of mass shift:

Implementation Method 2

creating favorable flap-torsion coupling and increasing aerodynamic damping

Methodology Applied

Scientific EffectFlap-torsion coupling:

Implementation Method 3

creating favorable flap-torsion coupling and increasing aerodynamic damping, suppressing unstable aeroelastic modes

Methodology Applied

Scientific EffectAerodynamic damping: Damping

Data Source

PatentUS20260028962A1Wind turbine rotor blade

Publication Date: 2026.01.29 SIEMENS GAMESA RENEWABLE ENERGY AS

AI summary

A wind turbine rotor blade is provided including an inboard region and an outboard region including a spanwise section associated with the development of an unstable aeroelastic mode. The disclosed rotor blade includes a leading-edge corrective mass arranged within the spanwise section, which leading-edge corrective mass is adapted to move the center of mass of the spanwise section towards the leading edge in order to suppress the development of an unstable aeroelastic mode. A method of manufacturing a wind turbine rotor blade is also provided.