A method for imaging an acoustic standing wave in the presence of flowing gas is described. The optical power at the acoustic frequency in each pixel of a series of high-speed transmission electronic speckle pattern interferograms is used to map the steady-state pressure variations of an acoustic standing wave. The utility of the process is demonstrated by imaging the standing wave inside a transparent organ pipe.
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The behavior of standing waves near the end of an open pipe with low mean flow
The acoustic standing wave near the end of an open pipe is investigated using spectrally analyzed high-speed transmission electronic speckle pattern interferometry. It is shown that the standing wave extends beyond the open end of the pipe and the amplitude decays exponentially with distance from the end. Additionally, a pressure node is observed near the end of the pipe in a position that is not spatially periodic with the other nodes in the standing wave. A sinusoidal fit to the amplitude of the standing wave inside the pipe indicates that the end correction is well predicted by current theory.
more » « less- Award ID(s):
- 2109932
- NSF-PAR ID:
- 10494449
- Publisher / Repository:
- AIP Publishing
- Date Published:
- Journal Name:
- JASA Express Letters
- Volume:
- 3
- Issue:
- 5
- ISSN:
- 2691-1191
- Subject(s) / Keyword(s):
- ["organ pipe","musical acoustics","flow","standing waves","interferometry"]
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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