Aircraft Wing-Like Element Torque Control for Load Alleviation

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Solution Overview

Problem

The integration of large wing tip devices on aircraft increases structural loads, particularly at the wing root, due to reduced effective lever arm and limited planar areas, which complicates the integration of control surfaces and affects aerodynamic performance.

Innovation Solution

Aircraft equipped with a passive torque control device featuring a rotatable interface that supports the wing root of an additional wing-like element, allowing rotation in airflow to manage torque and reduce loads, utilizing a spring-based system for passive control and a damping unit to prevent flutter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large wing tip devices are integrated on aircraft, then aerodynamic performance is improved, but structural loads at the wing root increase

Engineering Contradiction:
Improveaerodynamic performanceVSAvoidstructural loads at wing root
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent applies a passive torque control device that allows the wing-like element to rotate dynamically in response to aerodynamic forces. The rotatable interface means enables the wing-like element to adjust its angle of incidence automatically, transforming from a static structure to a dynamic one that can adapt to varying flight conditions and reduce peak loads at the wing root.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of angle of incidence of the wing-like element by allowing rotation about a rotational axis. This parameter change is controlled passively through aerodynamic forces acting on the wing-like element itself, which create a torque that rotates the element to reduce the effective lever arm and thereby reduce structural loads at the wing root.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If wing tip devices are curved upwards with large angles, then aerodynamic performance is improved, but effective lever arm for load reduction is reduced

Engineering Contradiction:
Improveaerodynamic performanceVSAvoideffective lever arm
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent makes the wing-like element dynamic by allowing it to rotate about a rotational axis through the rotatable interface means. This enables the effective lever arm to vary dynamically - in normal flight conditions the wing-like element maintains its aerodynamic position, but under high load conditions it rotates to reduce the lever arm and thereby reduce the bending moment at the wing root.

Inventive Principle:
Principle #15Dynamics

3Reliability

If control surfaces are integrated into wing tip devices, then load alleviation capability is improved, but integration is hindered by small planar areas and profile depths

Engineering Contradiction:
Improveload alleviation capabilityVSAvoidintegration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the wing-like element itself serve multiple functions: it provides aerodynamic lift enhancement and simultaneously acts as the control surface for load alleviation. By allowing the entire wing-like element to rotate about the rotational axis, the system eliminates the need for separate control surfaces, thereby reducing integration complexity while maintaining load alleviation capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent extracts the control function from traditional control surfaces and integrates it directly into the wing-like element's motion. The rotation of the wing-like element about the rotational axis provides the load alleviation effect without requiring additional control surfaces, thereby simplifying the overall structure and reducing integration complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Force

If passive torque control device with rotatable interface is used, then structural loads are reduced, but device complexity increases

Engineering Contradiction:
Improvestructural loadsVSAvoidtorque control device complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent implements a self-service system where the wing-like element controls its own rotation through aerodynamic forces. The torque control device requires no external power source, sensors, or active control systems - the aerodynamic forces acting on the wing-like element automatically create the torque needed to rotate it to the optimal angle, thereby reducing structural loads without adding complex active 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 solution effectively reduces structural loads on the aircraft by adjusting the angle of incidence of the wing-like element in response to aerodynamic forces, minimizing lift and torque, thereby alleviating loads during gusts and maneuvers.

Implementation Method 1

The wing-like element is adapted to induce a rotation around the rotational axis in an air flow

Methodology Applied
Scientific EffectAerodynamic forces: Aerofoil

Implementation Method 2

the torque control device is adapted to limit the degree of rotation depending on a torque introduced into the interface means by the wing-like element

Methodology Applied
Scientific EffectTorque: Torque

Data Source

PatentEP3301016B1Aircraft with load reducing wing like element
Publication Date: 2020.12.23 AIRBUS OPERATIONS GMBH
  • EP3301016B1 patent drawingFigure 1a~1b
  • EP3301016B1 patent drawingFigure 2~3a
  • EP3301016B1 patent drawingFigure 3b~4b

AI summary

An aircraft comprises a fuselage, a wing (2) attached to the fuselage, a wing tip device (6) attached to a wing end (4) of the wing (2), at least one additional wing-like element (14) having a wing root (22), a wing leading edge (18) and a wing trailing edge (20), and a torque control device having a rotatable interface means. The torque control device is adapted for rotatably supporting the wing root of the wing-like element on the interface means under creation of a rotational axis (16) extending from the interface means into the wing-like element (14), about which rotational the wing-like element (14) is rotatable. The wing-like element (14) is adapted to induce a rotation around the rotational axis (16) in an air flow. The torque control device is adapted to limit the degree of rotation depending on a torque introduced into the interface means by the wing-like element (14) and the wing root (22) of the at least one wing-like element (14) is coupled with at least one of the wing tip device (6), the wing (2) and the fuselage through the torque control device such that the leading edge (18) extends into an airflow surrounding the aircraft.