Aircraft Wing Heated Air Stream for Cabin Noise Refraction

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Solution Overview

Problem

Aircraft cabin noise levels are elevated due to engine and exhaust stream noise, particularly during takeoff and ascent, which affects passenger and crew comfort.

Innovation Solution

A method involving a heated stream of air produced by heating the leading edge of an aircraft wing, creating a temperature gradient that refracts noise away from the cabin, using electrical heaters or hot bleed air routed within the wing to form a heated air stream between the engine exhaust and fuselage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If engine power is increased to improve aircraft performance during takeoff and ascent, then propulsion capability is improved, but cabin noise levels increase

Engineering Contradiction:
Improveengine propulsion capabilityVSAvoidcabin noise levels
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

A stream of heated air is introduced as an intermediary substance between the engine exhaust and the cabin. This heated air stream refracts acoustic noise waves away from the cabin, reducing noise levels by approximately 53 decibels while allowing the engine to operate at high power settings during takeoff and ascent.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The temperature of the air stream is changed to create a temperature gradient that refracts sound waves. By heating air to a temperature sufficient to create refraction (but not high enough to cause thermal damage), the system alters the acoustic parameter of the medium through which sound travels, thereby redirecting noise away from the cabin.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If heated air stream is introduced to refract noise away from the cabin, then cabin noise levels are reduced, but additional system complexity is introduced

Engineering Contradiction:
Improvecabin noise levelsVSAvoidnoise reduction system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The heated air stream system serves multiple functions: it refracts acoustic noise waves away from the cabin to reduce noise levels, and can potentially serve other aerodynamic or thermal management functions. This multi-functionality justifies the added system complexity by providing noise reduction as a primary benefit alongside other operational advantages.

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 approach effectively reduces noise levels in the aircraft cabin by diverting acoustic noise waves, resulting in a noticeable decrease in sound intensity, typically reducing noise levels by approximately 53 decibels, enhancing passenger comfort.

Implementation Method 1

A heated stream of air from a wing of an aircraft can be used to form, for example, a heated air temperature gradient to refract noise, created by an aircraft engine and its exhaust stream of air, away from an aircraft cabin

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

A heated stream of air can be produced at a leading edge of an aircraft wing by heating the leading edge of the wing using electrical heaters

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

Ambient air is heated as it passes around the heated leading edge to produce a heated stream of air

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3401213B1Aircraft cabin noise reduction systems and methods
Publication Date: 2023.03.29 THE BOEING CO
  • EP3401213B1 patent drawingFigure 1
  • EP3401213B1 patent drawingFigure 2
  • EP3401213B1 patent drawingFigure 3

AI summary

Systems and methods according to one or more embodiments are provided for reducing noise levels in a passenger cabin of an aircraft. In one example, an aircraft includes a wing coupled to a fuselage. The wing is configured to heat air to provide a first stream of air from a central portion of a wing segment of the wing extending between the fuselage and a first engine of an aircraft. The first stream of air is at a higher temperature than an adjacent stream of air from the wing.