Shape Memory Alloy Vortex Generator Flap Actuation

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Solution Overview

Problem

Fixed vortex generators on aircraft wings result in unnecessary drag and increased fuel consumption during cruise, as they remain deployed at all times, despite being most needed only during take-off and landing.

Innovation Solution

A deployable vortex generator system using a shape memory alloy actuator that rotates a flap between stowed and deployed positions based on temperature changes, minimizing structure and cost, with the flap being perpendicular to the aerodynamic surface during deployment and parallel during cruise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vortex generators are fixed and deployed at all times, then aerodynamic performance is maintained during take-off and landing, but drag and fuel consumption increase during cruise

Engineering Contradiction:
Improveaerodynamic performanceVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The vortex generator is designed to be dynamically deployable and retractable rather than fixed. The flap can rotate between a deployed position (perpendicular to the aerodynamic surface) during take-off and landing, and a retracted position (parallel to the surface) during cruise, allowing the system to adapt to different flight conditions and eliminate unnecessary drag during cruise while maintaining performance when needed

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If vortex generators are deployed only during take-off and landing, then fuel consumption is reduced during cruise, but the mechanism complexity increases

Engineering Contradiction:
Improvefuel consumptionVSAvoidactuation mechanism
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent utilizes temperature changes as the actuating parameter for the shape memory alloy. The SMA material changes its physical state based on temperature variations, automatically deploying the flap when cooling is needed (take-off/landing) and retracting when heating occurs (cruise), eliminating the need for complex electronic control systems while enabling conditional deployment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The shape memory alloy actuator is self-actuating and does not require external power sources, control systems, or manual intervention. The material automatically responds to temperature changes to deploy or retract the flap, significantly simplifying the overall device complexity while enabling deployable operation during specific flight conditions

Inventive Principle:
Principle #25Self-service

3Extent of automation

If a shape memory alloy actuator is used, then automatic deployment based on temperature changes is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveautomatic deploymentVSAvoidmanufacturing cost
Core Design Contradiction:
Extent of automationVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical actuation systems (motors, sensors, control electronics, linkages) with a passive shape memory alloy-based thermal actuation system. The SMA material directly converts thermal energy to mechanical motion, automatically deploying the flap in response to temperature changes without requiring external power or control systems, thereby reducing manufacturing complexity and cost despite the specialized material

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Reduces drag and fuel consumption by deploying the vortex generator only when needed, maintaining aerodynamic efficiency while minimizing exposure to airflow during cruise.

Implementation Method 1

A deployable vortex generator system using a shape memory alloy actuator that rotates a flap between stowed and deployed positions based on temperature changes

Methodology Applied
Scientific EffectShape memory alloy: Shape Memory Alloy

Data Source

PatentEP2801521B1Vortex generator using shape memory alloys
Publication Date: 2018.04.25 THE BOEING CO
  • EP2801521B1 patent drawingFigure 1~2
  • EP2801521B1 patent drawingFigure 3~4
  • EP2801521B1 patent drawingFigure 5~6

AI summary

In one embodiment, the disclosed vortex generator may include a flap (12); a bearing (16) configured to be mounted on a surface (20); an axle (14) retained in the bearing, the flap attached to the axle such that the flap rotates relative to the bearing about the axle; and an actuator (32) made of a shape memory alloy attached to the flap and to a support, the actuator shaped to receive the axle therethrough, such that a change in temperature of the actuator causes the actuator to rotate the flap relative to the bearing.