Multifunctional Aircraft Insulation Integrating Active Noise Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current thermal and acoustic insulation systems in aircraft, such as glass wool blankets, are ineffective at low frequencies and require large volumes, leading to weight and maintenance issues, while active noise control systems are complex and heavy, and existing moisture control systems increase maintenance efforts.

Innovation Solution

A multifunctional thermal and acoustic insulation system with a multilayer structure incorporating a core layer of glass wool sandwiched between continuous outer layers, integrated with functional components like sensors and actuators for active noise control and moisture monitoring, reducing installation effort and maintenance needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If glass wool blankets are used for thermal and acoustic insulation, then thermal insulation and high-frequency acoustic absorption are achieved, but low-frequency acoustic absorption is ineffective and weight increases due to required large volume

Engineering Contradiction:
Improveacoustic absorption effectivenessVSAvoidinsulation system weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent combines passive acoustic absorption (glass wool) with active noise control (electrodynamic actuators) into a single integrated insulation system. The actuators are embedded within the glass wool blanket structure, merging two separate functions into one unified system that addresses both high-frequency absorption and low-frequency active control without requiring separate large-volume components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The glass wool blanket is transformed into a multi-functional component that simultaneously provides thermal insulation, high-frequency acoustic absorption, and serves as a mounting structure for active noise control actuators. This universal approach eliminates the need for separate insulation blankets and active control systems, reducing overall weight and volume.

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

2Reliability

If active noise control actuators are subsequently installed in aircraft, then low-frequency noise reduction is achieved, but installation complexity and mechanical interference problems increase due to limited space

Engineering Contradiction:
Improvenoise reduction effectivenessVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The active noise control actuators are pre-integrated into the insulation system during manufacturing, rather than being installed subsequently in the aircraft. This preliminary action eliminates complex field installation procedures, wiring harness routing, and mechanical mounting challenges that would otherwise occur during aircraft maintenance or modification.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The insulation system and active noise control components are merged into a single pre-assembled unit. The actuators are embedded within the glass wool blanket structure during manufacturing, creating an integrated system that eliminates separate installation steps and reduces mechanical interference risks with other aircraft equipment.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If glass wool blankets are used for insulation, then thermal and acoustic damping are provided, but moisture accumulation occurs leading to increased weight and decreased insulation properties

Engineering Contradiction:
Improvethermal and acoustic insulation performanceVSAvoidinsulation system weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

Hygroscopic sensors are integrated into the insulation system to continuously monitor moisture levels within the glass wool blanket. This feedback mechanism enables real-time detection of moisture accumulation, allowing for timely maintenance intervention before significant weight increase and performance degradation occur.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The insulation system incorporates self-monitoring capabilities through integrated humidity sensors that automatically detect moisture levels. This self-service approach enables the system to alert maintenance personnel when dehumidification is needed, eliminating the need for manual inspection and ensuring optimal performance is maintained.

Inventive Principle:
Principle #25Self-service

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 system provides improved thermal and acoustic comfort with minimal installation effort and on-demand maintenance, reducing weight and maintenance costs by integrating functional components within the insulation structure, enhancing both thermal and acoustic performance across a broader frequency range.

Implementation Method 1

When the voltage is applied across the anode and the cathode, moisture is drawn away from the anode and toward the cathode on the inferior surface of the outer wall

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

materials having acoustic absorption properties, i.e., materials having the effect of reducing the intensity of sound waves by causing accelerated damping of said waves

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Implementation Method 3

multifunctional thermal and acoustic insulation system

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4344997B1Mulitfunctional thermal and acoustic insulation system for an aircraft
Publication Date: 2024.11.20 AIRBUS OPERATIONS GMBH
  • EP4344997B1 patent drawingFigure 1~2
  • EP4344997B1 patent drawingFigure 3A~4
  • EP4344997B1 patent drawingFigure 5~6

AI summary

A multifunctional thermal and acoustic insulation system (3) to be received between an inner surface (8) of an aircraft primary structure, such as an aircraft fuselage structure (2, 9), and a surface (11) of a panel arrangement (10) delimiting an aircraft cabin, the surface (11) facing away from the aircraft cabin, comprises a multilayer structure (7) and a plurality of functional components (12) formed integrally and non-exchangeably with the multilayer structure (7). The multilayer structure (7) has a thermal and acoustic damping performance and comprises, in a stacked arrangement, a continuous first outer layer (5), a core layer (4) and a continuous second outer layer (6). The core layer (4) is received between the first and second outer layers (5, 6) so that the first and second outer layers (5, 6) cover the core layer (4) at least on opposite sides thereof. Functions of the functional components (12) are related to at least one of the thermal and the acoustic damping performance of the multilayer structure (7) and the functional components (12) are provided on a first outer layer side of the core layer (4) and/or on a second outer layer side of the core layer (4).