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Modelling of Acoust...
Modelling of Acoustic Resonators Using the Linearized Navier Stokes Equations
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- Du, Lin (author)
- KTH,Competence Center for Gas Exchange (CCGEx)
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- Åbom, Mats (author)
- KTH,Competence Center for Gas Exchange (CCGEx)
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- Karlsson, Mikael (author)
- KTH,Competence Center for Gas Exchange (CCGEx)
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Knutsson, M. (author)
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(creator_code:org_t)
- 2016-06-15
- 2016
- English.
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In: SAE Technical Paper Series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
- Related links:
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https://urn.kb.se/re...
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https://doi.org/10.4...
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Abstract
Subject headings
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- To tune the acoustics of intake systems resonators are often used. A problem with this solution is that the performance of these resonators can be affected a lot by flow. First, for low frequencies (Strouhal-numbers) the acoustic induced vorticity across a resonator inlet opening will create damping, which can reduce the efficiency. Secondly, the vorticity across the opening can also change the end-correction (added mass) for the resonator, which can modify the resonance frequency. However, the largest problem that can occur is whistling. This happens since the vortex-sound interaction across a resonator opening for certain Strouhal-numbers will amplify incoming sound waves. A whistling can then be created if this amplified sound forms a feedback loop, e.g., via reflections from system boundaries or the resonator. To analyse this kind of problem it is necessary to have a model that allows for both sound and vorticity and their interaction. This means using a convected wave equation type of model is not sufficient. A better approach is to apply the linearized Navier Stokes equations, which will give a full model of the vortex-sound effects. In this paper an effort to apply this approach on a set of generic resonators is described. Besides the numerical results comparisons with experiments are also presented.
Subject headings
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)
Keyword
- Acoustic noise
- Acoustic resonators
- Linearization
- Orifices
- Strouhal number
- Viscous flow
- Vortex flow
- Vorticity
- Convected wave equations
- End corrections
- Feed-back loop
- Linearized navier-stokes equations
- Numerical results
- Resonance frequencies
- System boundary
- Vortex-sound interactions
- Navier Stokes equations
Publication and Content Type
- ref (subject category)
- kon (subject category)
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