An experimental investigation of noise generation and noise reduction in a pipe flow behind a discontinuous area enlargement
Abstract
Flow separation downstream of a discontinuous enlargement in the circular cross-sectional area of a pipe was studied. The turbulence is a source of plane waves and higher acoustical modes. Microphone measurements were made to study the pressure fluctuations in the compact source region of the acoustic waves, and the aerodynamically generated acoustic field behind the discontinuous enlargement is shown to dominate far downstream. The vibrations of the acoustical modes are discussed, and damping techniques using simple geometrical shapes are tested.
- Publication:
-
Unknown
- Pub Date:
- May 1986
- Bibcode:
- 1986eing.rept.....S
- Keywords:
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- Flow Distribution;
- Noise Generators;
- Noise Measurement;
- Noise Reduction;
- Pipe Flow;
- Flow Characteristics;
- Pressure Distribution;
- Sound Generators;
- Turbulent Flow;
- Acoustics