Porous Noise Attenuating Member for Engine Turbulence
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Solution Overview
Problem
Turbulent fluid flow in engine systems, such as internal combustion engines, generates undesirable noise due to pressure waves and natural frequency excitation, which existing noise attenuation technologies have not effectively addressed.
Innovation Solution
A noise attenuating member comprising a porous material wrapped around a core with radial openings, positioned in a fluid flow path to disrupt turbulent eddies and attenuate sound vibrations while allowing minimal interference with fluid flow, using a housing with secure fitting features for integration into engine systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a noise attenuating member is inserted in the fluid flow path to reduce turbulence-generated noise, then noise attenuation is improved, but fluid flow restriction and pressure drop increase
Solution Approach 1:
The noise attenuating member is constructed from porous material that allows fluid to pass through while attenuating noise. The porous structure provides acoustic absorption for turbulence-generated noise across a broad frequency range while maintaining sufficient fluid flow with minimal pressure drop penalty.
Solution Approach 2:
The noise attenuating member combines porous material with a support structure (such as a mesh or framework) to create a composite construction. This provides both acoustic attenuation performance and structural integrity to withstand engine operating conditions while minimizing flow restriction.
2Object-affected harmful factors
If a noise attenuating member is designed to attenuate noise across a broad frequency range, then noise attenuation effectiveness is improved, but device complexity increases
Solution Approach 1:
The porous material inherently provides broad-spectrum noise attenuation across turbulent flow frequencies without requiring complex tuned resonators or multi-stage structures. The porous structure absorbs acoustic energy across a wide frequency range through viscous dissipation and thermal conduction mechanisms.
Solution Approach 2:
By varying parameters such as porous material density, pore size distribution, and thickness, the noise attenuating member can be optimized to provide effective attenuation across the broad frequency range generated by turbulent flow without increasing structural 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 effectively reduces turbulence-generated noise with minimal pressure drop and fluid flow restriction, providing repeatable attenuation and durability against engine operating conditions.
Implementation Method 1
During most operating conditions of an aspirator or check valve the flow is classified as turbulent. This means that in addition to the bulk motion of the air there are eddies superimposed.
Implementation Method 2
The noise attenuating member is constructed from a porous material and has a hollow internal cavity that provides repeatable turbulence generated noise attenuation across a broad frequency range.
Implementation Method 3
The noise attenuating member is constructed from a porous material wrapped around a core with radial openings
Data Source
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AI summary
Noise attenuating members for use in noise attenuating units for engine systems are disclosed that include a core, having an interior surface defining a hollow inner cavity and a plurality of radial openings, and a porous material disposed about an exterior surface of the core. The porous material may be a strip which is engaged with the exterior of the core and wrapped around the core to form a plurality of layers of porous material. A noise attenuating unit is disclosed to include a housing, having an internal cavity, first port, and second port, and an attenuating member disposed within the internal cavity. A method of making a noise attenuating member is disclosed that includes providing a core having an hollow cavity and radial openings, providing a strip of porous material, and wrapping the strip of porous material about the core to form one or more layers.