Aircraft Air Diffuser With Porous Flow Conditioning for Noise Control
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Solution Overview
Problem
Aircraft environmental control systems face challenges in creating a quiet and comfortable cabin environment while balancing weight and complexity, as conventional air diffusers generate noise at high flow rates and increase weight and complexity.
Innovation Solution
The use of air diffusers with a duct, grille, and porous flow conditioner to create backpressure, reducing air velocity and noise, by positioning the porous flow conditioner within the outlet plenum to attenuate noise and manage air flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional air diffusers are used to maintain cabin air flow, then air circulation is achieved, but noise is generated at high flow rates
Solution Approach 1:
The patent employs a porous flow conditioner positioned in the outlet plenum of the duct. This porous material creates backpressure that reduces air velocity while allowing air flow to continue, thereby attenuating noise generated by high-velocity air flow through the diffuser assembly without significantly reducing the overall air flow rate required for cabin ventilation
Solution Approach 2:
The porous flow conditioner changes the physical parameters of air flow by creating backpressure that reduces velocity. This parameter change (velocity reduction) directly addresses the noise problem while maintaining adequate air flow rates for cabin ventilation, resolving the contradiction between noise reduction and productivity
2Object-affected harmful factors
If conventional air diffusers are used to maintain cabin air flow, then air circulation is achieved, but weight and complexity increase
Solution Approach 1:
The porous flow conditioner serves multiple functions simultaneously: it creates backpressure to reduce air velocity, attenuates noise, and maintains adequate air flow rates. This multi-functionality reduces the need for separate noise control devices, thereby reducing overall device complexity and weight while still achieving noise reduction
Solution Approach 2:
The patent merges the noise attenuation function with the existing air flow path by positioning the porous flow conditioner within the outlet plenum of the duct. This integration combines noise control with the air distribution system, eliminating the need for separate noise control components and reducing overall system complexity
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 provides a quiet aircraft cabin environment with reduced noise levels and lower weight and complexity, maintaining comfortable air flow rates while adhering to FAA regulations, thus optimizing fuel and maintenance costs.
Implementation Method 1
The porous flow conditioner is configured to create backpressure in the duct and to reduce a velocity of air flowing out of the porous flow conditioner toward the diffuser exit
Implementation Method 2
The porous flow conditioner may be configured to reduce noise generated by air flow through the air diffuser assembly, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to attenuate noise generated downstream of the porous flow conditioner.
Data Source
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AI summary
Aircraft, environmental control systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin are disclosed. The air diffusers include a duct (30), a grille (50), and a porous flow conditioner (60) positioned at least partially within an outlet plenum (36) of the duct. The porous flow conditioner is configured to create backpressure and to reduce a velocity of air flowing out of the porous flow conditioner, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow through the air diffuser assembly, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow downstream of the porous flow conditioner.