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Published on: February 3, 2014
Experimental study of the influence of low frequency flow modulation on the whistling behavior of a corrugated pipe
Ulf R Kristiansen1, Pierre-Olivier Mattei, Cedric Pinhede
1Acoustics Research Centre, Department of Electronics and Telecommunications, Norwegian University of Science and Technology, 7491 Trondheim, Norway. ulf.kristiansen@iet.ntnu.no
Abstract:
It is well known that airflow in a corrugated pipe can excite whistling at the frequencies of the pipe's longitudinal acoustic modes. This short contribution reports on the results of experiments where a low frequency, oscillating flow with velocity magnitudes of the same order as the airflow has been added. Depending on the oscillation strength, it has been found that this flow may silence the pipe or move the whistling to higher harmonics. It is also shown that the low frequency oscillation itself may excite higher frequency whistling sounds in the pipe.
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