Elastomeric Control Surface Gap Sealing for Noise Reduction

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Solution Overview

Problem

Flight control surfaces moving create gaps that lead to increased airframe acoustic noise, reduced aerodynamics, and increased drag, particularly during changes in flight direction like landing approaches.

Innovation Solution

A continuous moldline technology using an elastomeric control surface with an elastomer interface coupled to a fluid-dynamic body, filling joint gaps caused by movement and allowing for subtle control without exposing edges, thereby reducing noise and improving aerodynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional rigid control surfaces are used, then structural strength is maintained, but gaps are created during movement causing increased noise and drag

Engineering Contradiction:
Improveacoustic noise and dragVSAvoidcontrol surface structural strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies flexible elastomeric material to create a control surface that can conform and seal against the airframe during movement, eliminating gaps while maintaining structural integrity through the elastomer's inherent flexibility and strength properties

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses composite construction combining elastomeric material with internal reinforcement structures (such as ribs or spars) to achieve both the flexibility needed for gap elimination and the structural strength required for aerodynamic loads

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If control surface size is reduced to lower weight and power requirements, then performance is maintained through elastomer bridging, but structural rigidity may be compromised

Engineering Contradiction:
Improvecontrol surface weightVSAvoidcontrol surface rigidity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The elastomeric control surface uses flexible material that can provide sufficient rigidity for small control surfaces while enabling weight reduction, as the elastomer itself provides both structural support and sealing function

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The composite elastomeric construction allows reduced control surface size and weight while maintaining rigidity through the combined properties of the elastomer and any internal reinforcement structures

Inventive Principle:
Principle #40Composite materials

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 decreases acoustic noise and enhances aerodynamic efficiency by bridging gaps during flight control surface movements, allowing for equivalent performance with a smaller actuated control surface and reduced weight and power requirements.

Implementation Method 1

an elastomeric control surface comprising a control surface and an elastomer interface. The control surface is coupled to a fluid-dynamic body... such that a joint gap caused by movement of the control surface relative to the fluid-dynamic body is filled

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2653378B1Continuous moldline technology (CMT) elastomeric control surface
Publication Date: 2022.06.08 THE BOEING CO
  • EP2653378B1 patent drawingFigure 1~2
  • EP2653378B1 patent drawingFigure 3~4
  • EP2653378B1 patent drawingFigure 5

AI summary

A continuous moldline technology elastomeric control surface and methods are presented. A control surface (302) is coupled to a fluid-dynamic body (314). An elastomer interface (304) is coupled to the control surface (302) and the fluid-dynamic body (314) such that a joint gap (410) caused by movement of the control surface (302) relative to the fluid-dynamic body (314) is filled.