Wind Turbine Blade Flow Separation Control

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Solution Overview

Problem

Wind turbines experience power production losses due to flow separation at rotor blades, leading to reduced lift and increased drag, which existing technologies have not effectively addressed.

Innovation Solution

A system comprising sensors and a controller that detect airflow parameters to actively control flow separation at rotor blades, using actuators to stimulate the blades and reduce separation, thereby increasing lift and decreasing drag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wind turbines operate at high angles of attack or low wind speeds, then power production is maintained, but flow separation occurs causing stalling and power loss

Engineering Contradiction:

Improvepower productionVSAvoidflow separation control

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies mechanical vibration through actuators that generate controlled vibrations on the rotor blade surfaces. These vibrations modify the boundary layer flow characteristics, preventing flow separation and delaying stall onset. The vibrational energy helps maintain attached flow at higher angles of attack, thereby preventing stalling while maintaining power production in low wind speed conditions.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The system dynamically changes operational parameters by using sensors to detect airflow conditions and actuators to modify blade surface characteristics in real-time. This includes adjusting vibration frequency, amplitude, and location based on detected flow separation tendencies, allowing the turbine to maintain optimal performance across varying wind speeds and angles of attack without permanent structural modifications.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If flow separation is allowed to occur, then device complexity is reduced, but lift force decreases and drag increases

Engineering Contradiction:

Improveblade structureVSAvoidlift force

Core Design Contradiction:

Device complexityVSForce

Solution Approach 1:

Rather than complex passive geometric modifications to the blade airfoil, the patent employs relatively simple vibrational actuators mounted on the blade surface. These actuators generate controlled vibrations that actively prevent flow separation, maintaining high lift forces without requiring substantial structural redesign of the blade itself.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The system implements feedback control by using sensors to continuously monitor airflow parameters and feed this information to controllers that adjust actuator operation accordingly. This closed-loop control maintains optimal lift forces by preventing flow separation only when and where needed, rather than requiring overly complex blade designs that attempt to predict and prevent separation passively.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If flow separation is not controlled, then manufacturing cost is reduced, but power production loss increases

Engineering Contradiction:

Improveblade manufacturingVSAvoidpower production

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent employs vibrational actuators that can be integrated into existing blade manufacturing processes without requiring completely new blade designs. These actuators are relatively simple mechanical components that can be manufactured and installed with moderate complexity, avoiding the need for expensive custom airfoil geometries or complex passive flow control structures.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The system enables the wind turbine to actively manage its own performance by using onboard sensors and actuators to prevent flow separation in real-time. This self-regulating capability allows the turbine to maintain high power production across varying operating conditions without requiring overly complex manufacturing or external control systems.

Inventive Principle:

Principle #25Self-service

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 system effectively delays flow separation, enhancing lift force and reducing drag, resulting in increased power production for wind turbines across various wind speeds and angles of attack.

Implementation Method 1

flow separation at a surface of a wind turbine blade is actively controlled to prevent and/or delay stalling of the blade

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Implementation Method 2

stimulating the blade with an actuator to create turbulence

Methodology Applied

Scientific EffectBoundary layer control: Boundary Layer

Implementation Method 3

detecting, using the sensor, an airflow parameter of the rotor blade

Methodology Applied

Scientific EffectAirflow parameter detection:

Implementation Method 4

active control of flow separation at rotor blades using sensors and actuators

Methodology Applied

Scientific EffectActive flow control:

Data Source

PatentUS8057175B2Active control of a wind turbine blade

Publication Date: 2011.11.15 GE INFRASTRUCTURE TECH LLC

AI summary

A method and system for increasing power production of a wind turbine including a rotor, at least one rotor blade coupled to the rotor, at least one sensor, and a controller communicatively coupled to the sensor. A flow parameter of the rotor blade is detected, and operation of the wind turbine is controlled to reduce a flow separation at the rotor blade based at least partially on the flow parameter of the rotor blade.