Archives of Acoustics, 43, 2, pp. 313–321, 2018

Testing the Acoustic Silencers

Marek Dariusz PIERCHAŁA
KOMAG Institute of Mining Technology

Problems associated with designing silencers are presented. Results of direct tests of silencers for cooperation with systems of axial fans, as well as results of numerical tests of a two stage acoustic silencer, are given. The numerical tests enabled determining the distribution of acoustic field inside the silencer and in the surrounding area. In those tests A sound insertion losses for different variants of installation inside the silencer, as well as for two different types of absorbing material used to fill the silencer walls, were determined. Impact of design features of silencers on effectiveness of noise reduction is described. Also, a technical sketch of a universal silencer with significant noise reduction ($D_{ipS}$ = 39.1 dB) which can be successfully used in many ventilation systems is presented.
Keywords: silencers; aerodynamic noise; noise reduction; ventilation systems; numerical tests; acoustic field; sound absorbing cassettes; dispersing component
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Augustyńska D. et al. (2000), Evaluation of noise emission of machines [in Polish: Ocena emisji hałasu maszyn], CIOP, Warszawa.

Bies D.A., Hansen C.H. (2009), Engineering noise control. Theory and practice, Spon Press, London – New York.

Chang Y.C., Min-Chie Chiu M.C. (2010), Optimization of multi-chamber mufflers with reverse-flow ducts by algorithm of simulated annealing, Archives of Acoustics, 35, 1, 13–33.

Crocker M.J. (2007), Handbook of noise and vibration control, John Wiley & Sons Inc., New Jersey.

Cummings A., Astley R.J. (1996), Finite element computation of attenuation in bar-silencers and comparison with measured data, Journal of Sound and Vibration, 199, 3, 351–369.

Dowling J.F., Peat K.S. (2004), An algorithm for the efficient acoustic analysis of silencers of any general geometry, Applied Acoustics, 65, 211–227.

Engel Z., Zawieska W. (2010), Noise and vibrations in work processes [in Polish: Hałas i drgania w procesach pracy], CIOP-PIB, Warszawa.

Gołaś A. (1995), Computer methods in interior and environment acoustics [in Polish: Metody komputerowe w akustyce wnętrz i środowisku], AGH, Kraków.

Kirby R. (2001), Simplified techniques for predicting the transmission loss of a circular dissipative silencer, Journal of Sound and Vibration, 243, 3, 403–426.

Klekot G. (2012), Application of vibroacoustic energy propagation measures to monitor the condition of objects and as a tool in noise management [in Polish: Zastosowanie miar propagacji energii wibroakustycznej do monitorowania stanu obiektów oraz jako narzędzie w zarządzaniu hałasem], WNITE-PIB, Radom.

Kuttruff H. (1991), Room acoustic, Elsevier Science Publishers, Barking, New York.

Loua G., Wua T.W., Cheng C.Y. (2003), Boundary element analysis of packed silencers with a substructuring technique, Engineering Analysis with Boundary Elements, 27, 643–653.

Łapka G. (2009), Acoustic attenuation performance of a round silencer with the spiral duct at the inlet, Archives of Acoustics, 32, 4, 247–252.

Łapka G. (2009), Insertion loss of spiral ducts – measurements and computations, Archives of Acoustics, 34, 4, 537–545.

Pierchała M. (2011), A low-emission acoustic ventilation system of strategic importance [in Polish: Niskoemisyjny akustycznie system wentylacji obiektów znaczeniu strategicznym], Maszyny Górnicze, 1, 44-47.

PN-EN ISO 11820:2000: Acoustics – Measurement of noise attenuators at the place of installation [in Polish: Akustyka – Pomiary tłumików hałasu w miejscu zainstalowania].

PN-ISO 9613-2:2002: Acoustics – Sound attenuation during propagation in the open space. General method of calculation [in Polish: Akustyka – Tłumienie dźwięku podczas propagacji w przestrzeni otwartej. Ogólna metoda obliczania].

VDI 3760:1996-02: Computation and measurement of sound propagation in workrooms.

Wang C.N. (1999), Numerical decoupling analysis of a resonator with absorbent material, Applied Acoustics, 58, 109–122.

DOI: 10.24425/122379

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