Influence of geometry of channel on the flow noise parameters

• Autorzy: Gaj P. , Kopania J.
• Języki publikacji: EN

Abstrakty

EN

Acoustic emission through duct walls is an important problem in engineering acoustics. This phenomenon most commonly occurs in heating, ventilating and air-conditioning (HVAC) and other gas flow ducting (large industrial silencers). Many works focus on elaboration of more exact description of the acoustic field phenomena reflecting the real conditions in which these appliances operate. As a standard, circle or rectangular ducts are used in ventilation systems. However, technical conditions during the installation of the HVAC system, due to the limitation of the assembly space, require often the use of channels with other geometries. This paper presents aeroacoustical parameters of three most common cross-sectional shapes of air-moving ductwork. The rectangular, square with roundedcorners and circular ducts were studied. The "natural" duct attenuation, which is a consequence of duct shape or noise breakout and involves a diminution of the internally propagated sound power was observed. Natural duct attenuation can be a useful way of reducing sound power levels in long runs of duct.

Słowa kluczowe

EN

HVAC; noise emission; shape duct; insertion loss

PL

HVAC; emisja hałasu; kształt kanału; tłumienność wtrąceniowa

• Wydawca: Wydawnictwo Politechniki Łódzkiej
• Czasopismo: Mechanics and Mechanical Engineering
• Rocznik: 2018
• Tom: Vol. 22, nr 2
• Strony: 541--551
• Opis fizyczny: Bibliogr. 18 poz., rys., 1 wykr.

Twórcy

autor

Gaj P.

• Institute of Power Engineering, OTC - Thermal Technology Branch ,,ITC" in Lodz, 113 Dabrowskiego Street, 93-208 Lodz, Poland

autor

Kopania J.

• Lodz University of Technology, 266 Piotrkowska Street,90-924 Lodz, Poland

Bibliografia

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• [2] Liao, J.: Analysis of Acoustic Energy Propagation in a Circular Duct to Improve the Accuracy of In-duct Noise Measurement. Ph.D. dissertation, Tennessee Technological University, 1990.
• [3] Howe, M. S.: Lectures on the Theory of Vortex-Sound, Theory of Vortex-Sound, Cambridge University Press, 32-33, 2002.
• [4] Howe, M. S.: Vorticity and the theory of aerodynamic sound, Journal of Engineering Mathematics, 41, 367-400, 2001.
• [5] Watanabe, K.: A Study on Noise Generated by the Air Flow in Duct System. Journal of the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan, 37, 5, 22-23, 1963.
• [6] Shiokawa, H., Itamoto, M.: On Sound Characteristics of Straight Glass Fiber Ducts, Journal of Architecture, Planning and Environmental Engineering, Architectural Institute of Japan, 435, 9-15, 1993.
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• [8] Ishihara, K.: Study on Acoustics Characteristics of Straight Duct with Some Holes, Transactions of the Japan Society of Mechanical Engineers, 74, 332-338, 2008.
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• [10] Ishihara, K.: Study on Acoustics and Flow Noise Characteristics of Bending Duct, Transactions of the Japan Societyof Mechanical Engineers 77, 1282-1291, 2011.
• [11] Vidal, A., Vinuesa, R., Schlatter, P., Nagib, M. H.: Influence of corner geometry on the secondary flow in turbulent square ducts , International Journal of Heat and Fluid Flow, 67, 69-78, 2017.
• [12] Vidal, A., Vinuesa, R., Schlatter, P., Nagib, M. H.: Reprint: Influence of corner geometry on the secondary flow in turbulent square ducts, International Journal of Heat and Fluid Flow, 67, 94-103, 2017.
• [13] PN-EN 3741:2011 ,,Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms”
• [14] PN-EN ISO 7235:2009 ,,Acoustics. Laboratory measurement procedures for ducted silencers and air-terminal units. Insertion loss, flow noise and total pressure loss”.
• [15] Kopania, J., Kaczyński, R.: Selected aspects of automation in fan examinations on standardized test stand, Heating, Ventilation and Air Conditioning, SIGMA-NOT, 42/2, 76-81, 2010.
• [16] Lin Z., Shao X., Yu Z., Wang L.: Effects of finite-size heavy particles on turbulent flows in a square duct, Journal of Hydrodynamics, 29:2, 272-282, 2017.
• [17] Yao J., Zhao Y., Fairweather M.: Numerical simulation of turbulent flow through a straight square duct, Applied Thermal Engineering Applied Thermal Engineering, 91, 2015.
• [18] Bradshaw P.: Turbulent secondary flows, Annu. Rev. Fluid Mech., 19, 53-74, 1987.

Uwagi

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).