Wing Tip Device Segmented Leading Edge Vortex Control

Solution Overview

Problem

Aircraft wings with longer spanwise wing tip devices are susceptible to leading edge flow separation due to the inboard advance of the wing tip vortex being impeded by minor surface discontinuities, leading to unpredictable drag increases and performance penalties.

Innovation Solution

The implementation of a wing tip device with a specific leading edge configuration, including a first, second, and third leading edge region with increasing sweep angles, and an alular-like projection to generate two discrete vortices, stabilizing the flow and preventing leading edge flow separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a longer spanwise wing tip device is used to reduce drag from wing tip vortices, then aerodynamic efficiency is improved, but leading edge flow separation occurs due to impeded vortex advance

Engineering Contradiction:

Improvedrag from wing tip vorticesVSAvoidflow separation predictability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The leading edge is divided into multiple regions (first, second, and third leading edge regions) with different sweep angles. This segmentation allows different portions of the leading edge to perform different functions: the first region allows vortex advance while the second and third regions with greater sweep angles prevent flow separation when the vortex is impeded by surface discontinuities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sweep angles are applied to different local regions of the leading edge. The second and third leading edge regions have greater sweep angles specifically where flow separation is most likely to occur when the vortex advance is impeded, providing localized protection against separation while maintaining overall vortex management.

Inventive Principle:

Principle #3Local quality

2Productivity

If the wing tip device span is increased to improve aerodynamic efficiency, then wing tip vortex energy recovery is enhanced, but surface discontinuities impede vortex advance causing flow separation

Engineering Contradiction:

Improveaerodynamic efficiencyVSAvoidflow separation from surface discontinuities

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The leading edge is divided into multiple regions (first, second, and third leading edge regions) with different sweep angles. This segmentation allows different portions of the leading edge to perform different functions: the first region allows vortex advance while the second and third regions with greater sweep angles prevent flow separation when the vortex is impeded by surface discontinuities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sweep angles are applied to different local regions of the leading edge. The second and third leading edge regions have greater sweep angles specifically where flow separation is most likely to occur when the vortex advance is impeded, providing localized protection against separation while maintaining overall vortex management.

Inventive Principle:

Principle #3Local quality

3Reliability

If leading edge high lift devices are added to prevent vortex advance, then flow separation is prevented, but device complexity increases

Engineering Contradiction:

Improveflow separation preventionVSAvoidleading edge high lift devices

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of adding mechanical high lift devices, the invention changes the geometric parameter (sweep angle) of the leading edge regions. The second and third leading edge regions have greater sweep angles than the first region, creating a passive geometric solution that prevents flow separation through flow attachment promotion rather than mechanical intervention.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention extracts the flow separation prevention function from mechanical high lift devices and embeds it directly into the leading edge geometry itself. The varying sweep angles of the leading edge regions inherently provide the flow control function, eliminating the need for separate high lift device mechanisms.

Inventive Principle:

Principle #2Taking out (Extraction)

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

This solution stabilizes the wing tip vortex, reducing drag penalties and improving the predictability of flow behavior at high angles of attack, thereby enhancing aircraft performance and handling characteristics.

Implementation Method 1

the second leading edge region is adapted to generate a first vortex

Methodology Applied

Scientific EffectVortex generation: Vortex Ring

Implementation Method 2

the third leading edge region is adapted to generate a second vortex which builds towards the tip end of the wing tip device

Methodology Applied

Scientific EffectVortex generation: Vortex Ring

Data Source

PatentUS12214865B2Wing tip device

Publication Date: 2025.02.04 AIRBUS OPERATIONS LTD

AI summary

A wing tip device for a fixed wing aircraft is disclosed having an alular-like projection, a first leading edge region having a first sweep angle, a second leading edge region outboard of the first leading edge region in a spanwise direction and having a second sweep angle greater than the first sweep angle, a third leading edge region outboard of the second leading edge region in the spanwise direction and adjacent a tip end of the wing tip device and having a third sweep angle greater than the first sweep angle. The second leading edge region is adapted to generate a first vortex, and the third leading edge region is adapted to generate a second vortex which builds towards the tip end of the wing tip device.