EFFECTIVENESS OF ELASTIC-WALLED CONCENTRIC TUBES IN ATTENUATING FLUIDBORNE NOISE IN AN EXPANSION CHAMBER ACOUSTIC FILTER,
Abstract
The report describes an experimental evaluation of several internal design modifications intended to improve the fluidborne noise reduction provided by an expansion-chamber type acoustic filter over the frequency range of 40 to 1000 Hertz (Hz) modifications included: The installation of a number of combinations of elastic-walled tubes concentrically positioned in the expansion chamber. A set of many small diameter orifices drilled in two of the concentrically positioned tubes. A baffle installed at the inlet end of the expansion chamber between a single concentric tube and the expansion chamber wall. Results indicate no consistent trends or order relating attenuation and the number of concentric elastic-walled tubes in the expansion chamber, over the frequency range of interest. A significant improvement in attenuation over that obtained by the expansion chamber alone was noted, however, when the smaller of the two tubes having drilled orifices was installed. Installation of a baffle brought further improvement in attenuation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1966
- Accession Number
- AD0645111
Entities
People
- E. Kakaley