Fluidic Lift Augmentation via Boundary Layer Control Ports

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Solution Overview

Problem

Current aircraft designs face limitations in achieving high lift due to boundary layer separation and thickening, particularly in multi-element configurations, which restrict maximum lift levels and efficiency during take-off and landing.

Innovation Solution

A system comprising a main wing element, slat, and flap with strategically located ports and fluidic devices that regulate fluid flow to control boundary layer flow, allowing for simultaneous ingestion and expulsion of fluid to manage flow over the wing elements, thereby enhancing lift and reducing drag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If boundary layer flow is not controlled over multi-element wing configurations, then the system is simpler, but boundary layer separation and thickening limit maximum lift levels

Engineering Contradiction:
Improvesystem complexityVSAvoidmaximum lift level
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The wing surface is segmented into multiple zones with ports distributed across the slat, main wing element, and flap. This segmentation allows localized boundary layer control at different critical locations, preventing separation and thickening that would otherwise limit maximum lift levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Ports are strategically positioned at specific locations where boundary layer separation and thickening are most problematic. The fluidic devices provide localized flow regulation exactly where needed, rather than uniform control across the entire wing surface, thereby maintaining high lift while managing complexity.

Inventive Principle:
Principle #3Local quality

2Speed

If wing area is increased to reduce stall speed, then stall speed decreases, but cruise drag increases

Engineering Contradiction:
Improvestall speedVSAvoidcruise drag
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

Instead of changing the physical wing area, the invention changes the flow parameters over the existing wing surface by using ports and fluidic devices to control boundary layer behavior. This allows achieving lower stall speeds through improved flow attachment and delayed separation without increasing wing area, thereby avoiding increased cruise drag.

Inventive Principle:
Principle #35Parameter changes

3Force

If ports are added with fluidic devices for boundary layer control, then lift coefficients improve and stall is delayed, but device complexity increases

Engineering Contradiction:
Improvelift coefficientVSAvoiddevice complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The fluidic devices connected to multiple ports serve multiple functions: they regulate fluid flow to control boundary layer attachment, delay separation, prevent thickening, and maintain high lift coefficients across different flight conditions. This multi-functionality achieves superior lift performance while managing device complexity through versatile components.

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

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 system improves lift coefficients and delay stall, resulting in shorter take-off and landing distances, increased payload capacity, and reduced structural fatigue, while maintaining aerodynamic efficiency across a range of angles of attack and flight conditions.

Implementation Method 1

at least one fluidic device operable to simultaneously regulate fluid flow into and out of the at least one port in the slat, the at least one port in the main wing element and at least one port in the flap to control boundary layer flow over the slat, the main wing element and the flap

Methodology Applied
Scientific EffectBoundary layer flow control: Boundary Layer

Data Source

PatentEP1951568B2Lift augmentation system and associated method
Publication Date: 2019.11.13 THE BOEING CO
  • EP1951568B2 patent drawingFigure 1A~1B
  • EP1951568B2 patent drawingFigure 2
  • EP1951568B2 patent drawingFigure 3A~3D

AI summary

A system and method for generating lift provided by a multi-element aircraft wing are provided. The system includes a main wing element (14), a slat (12) interconnected to the main wing element, and a flap (16) interconnected to the main wing element. The system also includes at least one port (s1, s2, ml, m2, m3, m4, m5, fl, f2, f9, f4, f5) defined in at least one of the slat, main wing element, and flap. In addition, the system includes at least one fluidic device operable to regulate fluid flow into and out of the at least one port to control boundary layer flow over at least one of the slat, main wing element, and flap.