Insertion Loss of Spiral Ducts - Measurements and Computations

• Autorzy: Łapka W.
• Języki publikacji: EN

Abstrakty

EN

This work presents measured and computed characteristics of insertion loss (IL) of spiral ducts. Numerical and experimental models of spiral ducts have been investigated. For the numerical modeling, a three dimensional model computed by the use of a finite element method in a COMSOL Multiphysics computer application has been used. For the experimental modeling, there has been made a spiral duct model by using a three dimensional rapid prototyping technique. An acoustic system with a round silencer has been ivestigated, and the spiral duct has been inserted at the inlet. IL is considered in this paper as the difference between the sound pressure level (SPL) [dB] probed at only one outlet point of the acoustic system without and with an acoustical filter (spiral duct), respectively. The results of measured and computed IL of spiral ducts presented in this paper confirm the fact that this newly discovered technical solution for attenuating sound in ducted systems has an applicable potential. There are visible small discrepancies between the measurements and computations. The results can differ due to the non ideal dimensions of the experimental model and the non ideal inlet and outlet surroundings of the experimental acoustic system. However, the IL characteristics of the computed model is almost wholly covered by the IL characteristics of the measured model.

Słowa kluczowe

EN

spiral duct; insertion loss; measurements; computations

• Wydawca: Instytut Podstawowych Problemów Techniki PAN ; Komitet Akustyki PAN ; Polskie Towarzystwo Akustyczne
• Czasopismo: Archives of Acoustics
• Rocznik: 2009
• Tom: Vol. 34, No. 4
• Strony: 537--545
• Opis fizyczny: Bibliogr. 13 poz., fot., wykr.

Twórcy

autor

Łapka W.

• Poznan University of Technology Institute of Applied Mechanics Division of Vibroacoustics and Biodynamics of Systems Piotrowo 3, 60-965 Poznan, Poland,

Bibliografia

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• [5] Łapka W., Acoustic attenuation performance of a round silencer with the spiral duct at the inlet, Archives of Acoustics, 32, 4 (Supplement), 247-252 (2007).
• [6] Łapka W., Sound propagation through circular ducts with spiral element inside, COMSOL Conference 2008, 4-6 November 2008, Hannover, Germany, 2008, Proceedings CD - 5 pages.
• [7] Łapka W., Cempel C., Acoustic attenuation performance of Helmholtz resonator and spiral duct, Vibrations in Physical Systems, 23, 247-252 (2008).
• [8] Łapka W., Cempel C., Computational and experimental investigations of a sound pressure level distribution at the outlet of the spiral duct, Archives of Acoustics, 33, 4 (Supplement), 65-70 (2008).
• [9] Łapka W., Cempel C., Noise reduction of spiral ducts, International Journal of Occupational Safety and Ergonomics (JOSE), 13, 4, 419-426 (2007).
• [10] Łapka W., Cempel C., Spiral waveguide and damper, Proceedings of the 36th International Congress & Exhibition on Noise Control Engineering, Global Approaches to Noise Control, Istanbul, Turkey, 2007, p. 191, Proceedings CD - 8 pages.
• [11] Łapka W., Cempel C., Insertion loss of spiral acoustic duct - computational modeling [in Polish:] Tłumienie wtrącenia akustycznego kanału spiralnego-modelowanie komputerowe, pp. 83-94, 35th Winter School on Vibroacoustical Hazards Suppressions, Wisła, Poland, 2007,.
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