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Experiments on sound generation in corrugated pipes with flow
Ulf R Kristiansen1, Geir A Wiik
1Acoustic Research Center, Norwegian University of Science and Technology, O.S. Bragstads plass 2b, 7491 Trondheim, Norway. ulf.kristiansen@iet.ntnu.no
The Journal of the Acoustical Society of America
|April 6, 2007
Summary
Acoustic measurements reveal that corrugated pipes generate sound, with sources localized at inflow ends or pressure maxima. Energy predominantly flows upstream in these pipes.
Area of Science:
- Acoustics
- Fluid Dynamics
- Aeroacoustics
Background:
- Corrugated pipes can generate significant noise due to flow-induced vibrations and resonances.
- Understanding sound generation mechanisms in such geometries is crucial for noise control.
Purpose of the Study:
- To investigate the acoustic properties of short corrugated pipes under flow conditions.
- To identify the effective sound source locations within the pipes.
- To analyze the energy flow patterns to understand sound propagation.
Main Methods:
- Experimental acoustic measurements were performed on short corrugated pipes with internal flow.
- Analysis focused on correlating sound levels with pipe geometry and flow parameters.
- Energy flow was studied in relation to standing wave pressure patterns.
Main Results:
- Sound generation is most effective when corrugations are at the pipe's inflow end.
- For fully corrugated pipes, sound sources are primarily located near pressure maxima of standing waves.
- The net energy flow within the pipe was predominantly observed in the upstream direction.
Conclusions:
- The position of corrugations significantly impacts sound generation efficiency.
- Standing wave pressure maxima are key regions for sound production in fully corrugated pipes.
- Upstream energy flow suggests complex acoustic feedback mechanisms within the pipes.
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