Elimination of a High-Frequency Narrow-Band Noise Component in a Low-Noise Automobile Wind Tunnel

960904

02/01/1996

Event
International Congress & Exposition
Authors Abstract
Content
The out-of-flow background noise spectrum in the test section of the full-scale low-noise automobile wind tunnel facility of BMW Technik GmbH in Munich showed a pronounced hump around 2 kHz Although this excess noise component was audible, it did not interfere with the automobile flow noise studies conducted in the tunnel An experimental study was performed to identify the source mechanism. It was found that the excess noise is generated by small cavities in the face side of the impeller blade tips When the cavities were closed the excess noise component completely dissappered The peak spectral level of the fan noise was reduced by as much as 30 dB The overall out-of-flow level reduction in the test section was 3 dB(A).
Meta TagsDetails
DOI
https://doi.org/10.4271/960904
Pages
12
Citation
von Heesen, W., Lindener, N., and Neise, W., "Elimination of a High-Frequency Narrow-Band Noise Component in a Low-Noise Automobile Wind Tunnel," SAE Technical Paper 960904, 1996, https://doi.org/10.4271/960904.
Additional Details
Publisher
Published
Feb 1, 1996
Product Code
960904
Content Type
Technical Paper
Language
English