The influence of viscosity of the working fluid on the sound production of centrifugal fans
Abstract
The influence of working fluid viscosity on the sound production of centrifugal fans was experimentally studied using a model fan with backward curved blades. The Reynolds number based on tip speed and diameter of the impeller varied over a range of Reynolds numbers by changing the air density at a constant temperature. Measurements of the harmonic and the random noise components are made at several points in the acoustic near field as well as in the far field. The results show that the sound production depends on the Reynolds number only for Re less than 100,000, while for Re greater than 100,000 the influence of the Reynolds number is negligible compared with the influence of other parameters. This is presumed to be true for all centrifugal fans.
- Publication:
-
Unknown
- Pub Date:
- May 1976
- Bibcode:
- 1976ivwf.rept.....B
- Keywords:
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- Aerodynamic Noise;
- Centrifugal Compressors;
- Sound Generators;
- Ventilation Fans;
- Air;
- Compressor Blades;
- Gas Density;
- Harmonics;
- Impellers;
- Noise Measurement;
- Radiation Sources;
- Random Noise;
- Similarity Theorem;
- Tip Speed;
- Viscosity;
- Working Fluids;
- Acoustics