Archives of Acoustics, 12, 3-4, pp. 177-197, 1987

Acoustic filters with a perforated tube

Gerard BRZÓZKA
Institute of Machine Construction and Operation of the Engineering College in Zielona Góra
Poland

A method of calculating acoustic properties of a low-pass filter with a perforated side baffle separating two wave-guides with constant cross-section areas is proposed. It is based on the principle of segmentation of the wave-guide into a series of elementary models which describe properties of acoustic element related to individual rows of perforation and segments of acoustic wave-guides, and on the description of acoustic properties of these models with the application of a transmission matrix with its properties of a chain matrix. Also relationships are given from which acoustic properties of a perforated baffle can be determined for a discrete parameter model at a laminar flow through orifices of the perforation.
Moreover, a calculation model for determining generally applied measures – insertion loss and transmission loss – was proposed on the basis of the transmission matrix of an acoustic filter determined with the presented method.
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Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).

References

G. BRZÓZKA, Taking the influence of medium motion into consideration in the description of an acoustic filter with perforated baffles (in Polish), Proc. XXXI Open Seminar on Acoustics OSA-84, Warsaw, 1984, 99-101.

G. BRZÓZKA, On calculations of acoustic filters with a perforated channel (in Polish), Proc. XXXI Open Seminar on Acoustics OSA-84, Warsaw, 1984, 102-106.

G. BRZÓZKA, A proposition of a specification of parameters of acoustic filters used in suction and exhaust systems of combustion engines (in Polish), Sc. Report of the Institute of Machine Construction and Operation of the Technical University of Wrocław, N° 43, Wrocław 1984, 29-37.

G. BRZÓZKA, A description of properties of expansion chamber mufflers with the application of transmission matrices (in Polish), Proc. Conf. NOISE Control '85, Cracow 1985, 173-177.