Nested Helmholtz Resonator Muffler for Broadband Noise Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust gas mufflers with Helmholtz resonators have limitations in covering a wide frequency range for effective engine noise damping.
Innovation Solution
The arrangement of a second coupling pipe within the first coupling pipe creates an annular gap, allowing two Helmholtz resonators to operate in different frequency ranges and overlap their frequency responses, thereby covering a broader frequency range for enhanced noise damping, with the option for a multi-piece construction and varying diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single Helmholtz resonator is used, then the structure is simple, but the frequency range covered is limited
Solution Approach 1:
The patent implements a nested configuration where the second coupling pipe is positioned inside the first coupling pipe, creating a compact dual-resonator structure. This nesting approach allows two Helmholtz resonators to occupy overlapping spatial volumes, effectively doubling the frequency range coverage without proportionally increasing the overall device footprint or structural complexity
Solution Approach 2:
The patent combines multiple Helmholtz resonators into a single integrated muffler assembly with shared housing and coupled exhaust gas inlet. By merging the resonators and their coupling pipes into one unified structure, the patent achieves extended frequency coverage while avoiding the complexity of separate resonator systems
2Adaptability or versatility
If two separate Helmholtz resonators are provided, then the frequency range is extended, but the device size increases
Solution Approach 1:
The patent places the second coupling pipe within the first coupling pipe, allowing the second Helmholtz resonator to be positioned concentrically or adjacently to the first resonator. This nesting strategy enables both resonators to function independently across different frequency ranges while occupying a compact, overlapping volume, thereby extending frequency coverage without linearly increasing the overall muffler size
Solution Approach 2:
The patent utilizes the annular gap between the first coupling pipe and second coupling pipe as a functional pathway for exhaust gas flow. By exploiting the radial dimension and creating an annular flow path, the patent accommodates two resonators in a compact configuration that would not be possible with simple linear arrangement, thus extending frequency range without proportionally increasing volume
3Device complexity
If the coupling pipes are arranged coaxially, then the structure is compact, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies that the second coupling pipe is arranged at least partially within the first coupling pipe in a coaxial or substantially coaxial manner. This nested coaxial arrangement achieves structural compactness while the patent addresses manufacturing precision by defining the annular gap dimensions and providing guidance on alignment tolerances to ensure proper acoustic coupling and exhaust gas flow distribution between the two resonators
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 configuration achieves extensive overall damping of engine noise by covering a substantially greater frequency range and allows for a compact twin Helmholtz resonator design with improved acoustic performance.
Implementation Method 1
The invention relates to an exhaust gas muffler of an internal combustion engine, comprising a muffler housing having an exhaust gas inlet and an exhaust gas outlet and comprising a first Helmholtz resonator... at least one second Helmholtz resonator is provided... overlapping frequency responses of both Helmholtz resonators hereby achieved, a substantially greater frequency range is covered so that very extensive overall damping of the engine noise is possible
Data Source
AI summary
An exhaust gas muffler of an internal combustion engine, including a muffler housing having an exhaust gas inlet and an exhaust gas outlet and including a first Helmholtz resonator made of a first housing portion that delimits a first Helmholtz volume and includes a first coupling pipe. At least one second Helmholtz resonator is provided made of a second housing portion that delimits a second Helmholtz volume and includes a second coupling pipe via which the second Helmholtz volume can be coupled to an exhaust gas flow A of the exhaust gas inlet. The second coupling pipe is arranged at least partly within the first coupling pipe, and both coupling pipes delimit an annular gap R via which the first Helmholtz volume can be coupled to the exhaust gas flow A.