Micro-perforated Air Silencer for Turbocharger Noise Reduction

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Solution Overview

Problem

Traditional air silencers for turbochargers are often large and heavy, causing vibration issues that can damage the turbine or compressor wheels due to engine vibrations and airflow, and they do not effectively attenuate noise across a wide frequency range.

Innovation Solution

A smaller and lighter air silencer design featuring micro-perforated plates with circular openings less than 1 mm in diameter, separated by a honeycomb spacer matrix, which creates sub-cavities that function as independent noise attenuators, effectively reducing noise at specific frequencies by utilizing friction losses and resonance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a large and heavy silencer is used to attenuate noise, then noise attenuation is improved, but vibrations increase and reliability deteriorates

Engineering Contradiction:
Improvenoise attenuationVSAvoidturbocharger reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the physical parameters of the silencer by using micro-perforated plates with hole diameters of 0.1-1mm instead of traditional large perforations, and by incorporating a honeycomb spacer matrix with specific cell dimensions. These parameter changes enable effective noise attenuation at lower frequencies while maintaining a compact, lightweight structure that does not exacerbate vibrations or compromise turbocharger reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The silencer employs a composite structure combining micro-perforated metal plates with a honeycomb spacer matrix material. This composite approach creates multiple resonant cavities that enhance noise attenuation across a broader frequency range while keeping the overall silencer size and weight reduced, thereby preventing vibration-induced damage to the turbocharger

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a traditional silencer design is used, then noise attenuation is provided, but the frequency range of attenuation is limited

Engineering Contradiction:
Improvenoise attenuationVSAvoidfrequency range
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The silencer is segmented into multiple functional zones using micro-perforated plates with varying hole densities and a honeycomb spacer matrix with different cell sizes. This segmentation creates multiple resonant frequencies and attenuation zones, enabling the silencer to effectively attenuate noise across a broad frequency spectrum rather than at a single frequency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the silencer are designed with locally optimized properties: micro-perforated plates with specific hole patterns in certain zones, and honeycomb structures with varying cell dimensions in other zones. This local quality variation allows each section to target specific frequency ranges, collectively providing broad-spectrum noise attenuation

Inventive Principle:
Principle #3Local quality

3Weight of stationary object

If a compact silencer is used, then weight and size are reduced, but noise attenuation performance may be compromised

Engineering Contradiction:
Improvesilencer weightVSAvoidnoise attenuation
Core Design Contradiction:
Weight of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The honeycomb spacer matrix is nested within the silencer structure, creating multiple resonant cavities in a compact arrangement. This nested configuration allows the silencer to achieve effective noise attenuation volumes without increasing overall size or weight, as the honeycomb cells are efficiently packed within the available space

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The micro-perforated plates with 0.1-1mm holes and the honeycomb spacer matrix create a porous structure that provides high surface area for noise attenuation in a compact volume. This porous configuration enables effective noise attenuation performance without requiring a large, heavy structure

Inventive Principle:
Principle #31Porous materials

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 new design provides significantly wider noise attenuating bandwidth and reduced pressure loss, improving the performance of the turbocharger by minimizing vibrations and effectively managing noise across a broader frequency range compared to traditional silencers.

Implementation Method 1

effectively reducing noise at specific frequencies by utilizing friction losses and resonance

Methodology Applied
Scientific EffectFriction losses: Friction

Implementation Method 2

effectively reducing noise at specific frequencies by utilizing friction losses and resonance

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3692264B1An air silencer connectable to a compressor part of a turbocharger
Publication Date: 2021.12.01 WARTSILA FINLAND OY
  • EP3692264B1 patent drawingFigure 1
  • EP3692264B1 patent drawingFigure 2~3

AI summary

Invention relates to an air silencer (24) connectable a compressor part (12) of a turbo-charger (10) comprising a flange part (26) provided with an air passage (54) configured to be connectable with an air intake opening of the compressor part in an air tight manner, a number of noise attenuating baffles (50) being separated from each other so as to form air passage (54) for an inlet air through the air silencer (24) to the air passage (54), the baffles (50) comprise a micro-perforated plate (56.1, 56.2) provided with a micro-perforation (53), and a back plate (60), and a space (57) arranged between the micro-perforated plate (56.1, 56.2) and the back plate (60) which space (57) comprises a spacer matrix (58.1, 58.2) providing a number of sub cavities (64) in the space (57) fluidly communicating with the micro-perforation (53).