Aircraft Nacelle Panel Hot Air Duct Orientation

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Solution Overview

Problem

The existing solutions for aircraft nacelles that combine acoustic and frost treatments do not optimize the flow of hot air to the panels, leading to inefficiencies in defrosting and potential pressure imbalances.

Innovation Solution

The aircraft nacelle design includes a panel with an acoustically resistive layer, honeycomb structure, and reflective layer, featuring channels that direct hot air from an annular duct to the inner duct at an angle of less than 60 degrees, enhancing the flow and distribution of hot air for effective frost treatment and acoustic absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the mouth of the duct is oriented perpendicular to the flow direction in the annular duct (conventional design), then the structure is simple and easy to manufacture, but the flow of hot air to the panel is not optimized, leading to poor concentration and distribution

Engineering Contradiction:
Improveefficiency of hot air delivery to panelVSAvoidorientation angle of duct mouth
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the orientation angle parameter of the duct mouth from the conventional perpendicular (90 degrees) to an angle between 10 and 60 degrees relative to the flow direction in the annular duct. This parameter modification optimizes the flow direction to better align with the panel surface, improving hot air concentration and distribution efficiency without requiring complex additional components

Inventive Principle:
Principle #35Parameter changes

2Productivity

If channels extend perpendicular to the flow direction in the annular duct (conventional design), then the manufacturing is simplified, but the hot air flow from the annular duct to the channels is not optimized

Engineering Contradiction:
Improveflow optimization from annular duct to channelsVSAvoidchannel orientation in intermediate piece
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent modifies the orientation parameter of the channels in the intermediate piece, changing them from perpendicular to the flow direction to an angle between 10 and 60 degrees. This alignment optimization improves the flow transition from the annular duct to the channels, enhancing overall system efficiency while maintaining manufacturability

Inventive Principle:
Principle #35Parameter changes

3Productivity

If hot air occupies the volume of alveolar structure cells (conventional design), then the defrosting coverage is distributed, but the concentration of hot air against the wall is reduced, lowering defrosting efficiency

Engineering Contradiction:
Improvedefrosting efficiencyVSAvoidvolume occupation of hot air
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the hot air flow path by introducing an intermediate piece with channels that direct hot air in a concentrated stream along the wall surface rather than allowing it to disperse into the alveolar structure cells. This segmentation maintains hot air concentration where needed for efficient defrosting while preventing pressure imbalances

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by concentrating hot air delivery specifically at the wall surface through optimized channel orientation and the intermediate piece structure, rather than distributing it uniformly throughout the alveolar volume. This localized concentration maximizes defrosting efficiency at the critical interface

Inventive Principle:
Principle #3Local quality

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 design improves the concentration and homogenization of hot air, increasing the efficiency of defrosting while maintaining optimal pneumatic pressure, reducing the risk of air penetration and ensuring safe temperature discharge.

Implementation Method 1

the hot air is in permanent contact with the skin to be defrosted, which makes it possible to improve the exchanges and to reduce the temperature of the hot air discharged

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

hot air circulates in the annular duct, making several turns therein

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

by using the principle of Helmholtz resonators

Methodology Applied
Scientific EffectHelmholtz resonance: Helmholtz Resonance

Implementation Method 4

panels or coatings aimed at absorbing part of the sound energy

Methodology Applied
Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentEP2578842B1Aircraft nacelle comprising a device for supplying hot air to a panel combining acoustic and ice treatments
Publication Date: 2016.04.06 AIRBUS OPERATIONS (SAS)
  • EP2578842B1 patent drawingFigure 1~2
  • EP2578842B1 patent drawingFigure 3
  • EP2578842B1 patent drawingFigure 4A~6

AI summary

The object of the invention is an aircraft nacelle comprising a lip extended by an internal duct forming an air inlet, a front frame delimiting with said lip an annular duct (40) in which hot air circulates, and a panel for acoustic treatment comprising from the outside in an acoustically resistive layer, at least one honeycomb structure and a reflective layer, as well as channels for channeling hot air, at least one duct (98) with an opening (100) which opens into the annular duct (40) being provided to convey the hot air to the panel for acoustic treatment, characterized in that the opening (100) allows the hot air to be channeled in a direction (102) which forms an angle β less than 60° with the direction (42) of flow of the hot air in the annular duct (40).