Cruise Mini Flap for Aircraft Wing Lift and Drag Optimization

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Solution Overview

Problem

Modern long-range commercial airplanes face high fuel consumption due to low wing lift coefficients, leading to increased aerodynamic drag and restricted cruise altitudes, which limits direct route options and increases fuel costs.

Innovation Solution

The introduction of a cruise mini flap (CMF) at the aircraft wing's trailing edge, which can be mechanically adjusted to modify camber, area, and shape, creating a cavity that reduces drag and increases lift, allowing for higher altitudes and improved aerodynamic efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the aircraft uses a wing profile designed for low aerodynamic drag with lift coefficient CL within 0.45-0.6, then the aerodynamic drag is reduced, but the wing loading is high and the aircraft cannot reach optimal cruise altitude after take-off

Engineering Contradiction:
Improveaerodynamic dragVSAvoidfuel consumption
Core Design Contradiction:
Loss of energyVSUse of energy by moving object

Solution Approach 1:

The patent applies a movable cruise mini flap at the trailing edge of the wing that can be dynamically adjusted during flight. The flap changes the wing's camber and effective lift coefficient based on flight conditions, allowing the aircraft to achieve higher lift coefficients (0.7-0.8) when needed during take-off and climb, while maintaining the original low-drag wing profile design for cruise flight.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention modifies only the local trailing edge region of the wing by adding a small cruise mini flap, rather than changing the entire wing profile. This localized modification allows the aircraft to achieve higher lift coefficients without substantially increasing the overall aerodynamic drag of the wing, as the majority of the wing surface maintains its original low-drag characteristics.

Inventive Principle:
Principle #3Local quality

2Speed

If the aircraft cruises at lower altitude due to high wing loading, then the aerodynamic drag increases, but the ground speed decreases which also increases fuel consumption

Engineering Contradiction:
Improveground speedVSAvoidaerodynamic drag
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The dynamic adjustment of the cruise mini flap allows the aircraft to optimize its lift-to-drag ratio at different flight stages. During take-off and climb, the flap is deployed to increase lift and enable higher cruise altitude achievement. During cruise, the flap is retracted to maintain low drag, allowing the aircraft to sustain higher speeds and reach optimal cruise altitudes despite the added flap mechanism.

Inventive Principle:
Principle #15Dynamics

3Force

If conventional trailing edge flaps are used to modify camber and area, then the lift coefficient increases, but the aerodynamic drag substantially grows

Engineering Contradiction:
Improvelift coefficientVSAvoidaerodynamic drag
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The invention segments the trailing edge modification into a small, separate cruise mini flap component rather than using a large conventional flap. This segmented approach allows for precise control of lift coefficient increases while minimizing the impact on aerodynamic drag, as the mini flap creates only localized flow modifications rather than large-scale flow changes associated with conventional flaps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cruise mini flap modifies only the local flow characteristics at the trailing edge, creating a cavity that enhances lift through localized pressure distribution changes. This localized modification achieves higher lift coefficients without the substantial drag increase that would result from modifying the entire trailing edge with a conventional flap system.

Inventive Principle:
Principle #3Local quality

4Strength

If the trailing edge is made blunt to increase structural strength, then the wing can withstand higher loads, but the aerodynamic drag increases and lift coefficient decreases

Engineering Contradiction:
Improvestructural strengthVSAvoidaerodynamic drag
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent introduces a movable cruise mini flap that can be deployed or retracted based on flight conditions. When retracted, the trailing edge maintains its original streamlined shape for low drag. When deployed, the mini flap creates a controlled cavity that enhances lift while the underlying structural trailing edge remains intact, preserving both strength and aerodynamic efficiency.

Inventive Principle:
Principle #15Dynamics

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 CMF enhances lift coefficients to 0.7-0.8 while maintaining low drag, reducing fuel consumption, extending flight distance, and lowering maintenance costs by reducing engine wear and emissions.

Implementation Method 1

The cruise mini flap (hereinafter CMF) according to the disclosure is part of the aircraft wing or the trailing edge flap and it can be used to modify the camber and the area of the aircraft wing and to create a cavity within the wing trailing edge

Methodology Applied
Scientific EffectAerodynamic flow:

Implementation Method 2

a supercritical wing profile with a cavity in the trailing edge has lower aerodynamic drag than a blunt trailing edge

Methodology Applied
Scientific EffectAerodynamic drag reduction:

Implementation Method 3

provides means for increasing the wing lift coefficient to the level of 0.7-0.8 so that the drag coefficient does not grow substantially

Methodology Applied
Scientific EffectLift generation:

Data Source

PatentEP3498595B1Aircraft wing comprising cruise mini flaps
Publication Date: 2020.12.02 LAUK PEEP
  • EP3498595B1 patent drawingFigure 1a~1c
  • EP3498595B1 patent drawingFigure 2
  • EP3498595B1 patent drawingFigure 3

AI summary

This invention provides construction variants of a cruise miniflap that is added to the trailing edge flap of an aircraft wing and can be used for improving the aerodynamic properties of an aircraft. In the rear edge of the cruise miniflap, it has a cavity with a height of up to 1 % of the wing chord.