A study of active control of noise in ducts
Abstract
New results in the development of a one-dimensional noise cancellation system in a duct are presented. Noise in the duct is cancelled out by sound waves generated by sound radiators mounted either on the duct walls or placed remotely in a side branch of the duct. It is found that the sound field created by the radiators can achieve a high degree of noise cancellation primarily at low frequencies and in the region of plane wave propagation under the first cross-made cutoff frequency. The overall arrangement of the system is described in a schematic diagram, and the characteristics of the sound field are explained mathematically in a series of eigenfunctions for the duct cross section.
- Publication:
-
ASME Journal of Vibration Acoustics
- Pub Date:
- July 1984
- Bibcode:
- 1984ATJVA.106..399T
- Keywords:
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- Acoustic Ducts;
- Active Control;
- Noise Reduction;
- Piston Theory;
- Sound Fields;
- Sound Pressure;
- Acoustics