Particulate Filter Labyrinth Duct for Exhaust Acoustic Adaptation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional particulate filters for motor vehicles have a narrow frequency spectrum, primarily attenuating high-frequency exhaust noise components, which alters the original sound characteristic of vehicles and fails to meet legal noise emission standards, limiting consumer differentiation based on exhaust sound.

Innovation Solution

A particulate filter design featuring a labyrinth-type through flow duct configuration with a ring system between the core and casing, allowing reduced attenuation of high-frequency noise components and enabling acoustic adaptation of the exhaust sound by adjusting the ring configuration, thereby expanding the frequency spectrum and improving particulate absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional particulate filters are used with core surrounded by casing and alternately closed flow ducts, then high-frequency noise components are attenuated, but the frequency spectrum becomes narrow and exhaust sound characteristic is lost

Engineering Contradiction:

Improvehigh-frequency noise attenuationVSAvoidfrequency spectrum breadth

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The through-flow duct is segmented into multiple sections with different configurations. The first section has a first cross-sectional area and the second section has a second cross-sectional area, allowing different frequency ranges to be treated differently. This segmentation enables the filter to maintain high-frequency attenuation while preserving low-frequency sound characteristics.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the through-flow duct are given different local properties. The first section is designed with specific geometric characteristics to attenuate high-frequency noise, while the second section is designed to preserve low-frequency components. This local differentiation allows the filter to have selective acoustic properties across different frequency ranges.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the entire particulate filter configuration is changed to expand frequency spectrum, then acoustic optimization is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improvefrequency spectrum breadthVSAvoidfilter configuration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The acoustic optimization function is extracted from the entire filter system and concentrated in the through-flow duct geometry. By modifying only the duct's cross-sectional area distribution along its length, the patent achieves frequency spectrum expansion without changing the core, casing, or other major filter components, thereby reducing manufacturing complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of changing the filter configuration in multiple dimensions (core structure, casing shape, mounting position), the patent achieves acoustic optimization by varying the cross-sectional area along the longitudinal dimension of the through-flow duct. This one-dimensional approach simplifies the design and manufacturing process while achieving the desired acoustic performance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If high-frequency noise components are heavily attenuated, then noise emission standards are met, but exhaust sound characteristic and vehicle identification are lost

Engineering Contradiction:

Improvenoise emission levelVSAvoidexhaust sound characteristic

Core Design Contradiction:

Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The through-flow duct is designed with dynamically varying cross-sectional area along its length. The first section has a larger cross-sectional area to preserve low-frequency sound characteristics, while the second section has a smaller cross-sectional area to attenuate high-frequency noise. This dynamic geometry allows the filter to differentially treat different frequency components, meeting noise standards while preserving exhaust sound character.

Inventive Principle:

Principle #15Dynamics

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 results in a broader frequency spectrum for the exhaust noise, allowing for acoustic optimization without altering the entire filter configuration, while maintaining effective particulate filtration and reduced emissions, thus meeting noise standards and enabling vehicle sound differentiation.

Implementation Method 1

The through flow duct (9) has a labyrinth-type configuration with the aid of a ring (7) in the through flow duct

Methodology Applied

Scientific EffectLabyrinth flow path:

Implementation Method 2

high-frequency noise components can be attenuated to a lesser extent

Methodology Applied

Scientific EffectAcoustic attenuation: Acoustic Absorption

Data Source

PatentUS9976461B2Particulate filter for a motor vehicle

Publication Date: 2018.05.22 DR ING H C F PORSCHE AG

AI summary

A particulate filter for a motor vehicle has a casing (2) that allows through flow. A core (4) is accommodated in the casing (2) and allows through flow. The casing (2) has a longitudinal axis (3). A through flow duct (9) is formed between the casing (2) and the core (4) to allow the through flow of exhaust gas from an internal combustion engine of the motor vehicle. A ring (7) is arranged in the through flow duct (9) and gives the through flow duct (9) a labyrinth-type configuration.