Helmholtz resonators are normally an afterthought in the design of mufflers to target a very specific low frequency, usually the fundamental firing frequency of the engine. Due to space limitations in a complex muffler design, a resonator may have to be built by punching a few small holes on a thin-walled tube to create a neck passage into a small, enclosed volume outside the tube. The short neck passage created by punching a few small holes on a thin-walled tube can pose a great challenge in numerical modeling, especially when the boundary element method (BEM) is used. In this paper, a few different BEM modeling approaches are compared to one another and to the finite element method (FEM). These include the multi-domain BEM implemented in a substructure BEM framework, modeling both sides of the thin-walled tube and the details of each small hole using the Helmholtz integral equation and the hypersingular integral equation, and modeling just the mid surface of the thin-walled tube. The FEM and BEM solutions are used to estimate the effective neck length commonly used in an analytical solution. The effect of changing the locations of the holes is also investigated.
|Journal||SAE Technical Papers|
|State||Published - Jun 5 2019|
|Event||2019 SAE Noise and Vibration Conference and Exhibition, NVC 2019 - Grand Rapids, United States|
Duration: Jun 10 2019 → Jun 13 2019
Bibliographical noteFunding Information:
The research was partially supported by Advanced Exhaust Solutions and the Vibro-Acoustics Consortium.
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ASJC Scopus subject areas
- Automotive Engineering
- Safety, Risk, Reliability and Quality
- Industrial and Manufacturing Engineering