Experimental determination of the tonal noise sources in a centrifugal fan

In this work, an experimental study about the aerodynamic tonal noise sources in an industrial centrifugal fan with backward-curved blades has been carried out. Acoustic pressure measurements at the fan exit duct and pressure fluctuation measurements on the volute surface (specially in the vicinity of the volute tongue) have been made for different flow rates. The correlation of both pressure signals can lead to determine the zone of effective acoustic radiation. As was expected, the tonal noise generation is concentrated on the meridional plane of the impeller discharge, near the volute tongue and presents a strong dependence with the flow rate.

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Analysis of Relative Contributions of Tonal Noise Sources in Volute Tongue Region of a Centrifugal Fan

The Journal of the Acoustical Society of Korea ◽

10.7776/ask.2014.33.1.040 ◽

2014 ◽

Vol 33 (1) ◽

pp. 40 ◽

Cited By ~ 3

Author(s):

Cheolung Cheong

Keyword(s):

Centrifugal Fan ◽

Tonal Noise ◽

Noise Sources

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Noncontinuous noise calculated by room response function determined by experimental data

Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel nogo universiteta JOURNAL of Construction and Architecture ◽

10.31675/1607-1859-2021-23-6-117-128 ◽

2021 ◽

Vol 23 (6) ◽

pp. 117-128

Author(s):

A. I. Antonov ◽

V. I. Ledenev ◽

I. V. Matveeva ◽

M. A. Porozhenko

Keyword(s):

Experimental Determination ◽

Response Function ◽

Negative Impact ◽

Pulse Excitation ◽

Noise Sources ◽

Accurate Analysis ◽

Sound Fields ◽

Function Calculation ◽

Acoustic Conditions

Purpose: Experimental determination of the response room function and its use to estimate the acoustic conditions in rooms with noncontinuous noise sources.Methodology/approach: The detailed parameter calculation of noncontinuous sound fields using the response room function, which is the room response to pulse excitation. The response function can be calculated by analytical or numerical methods and by experimental measurements in production conditions the energy attenuation when a constant noise source is switched off.Findings: Noncontinuous noise has a negative impact on health. The effective noise reduction is determined by the complete and accurate analysis of its energy parameters. The noncontinuous noise estimation based on equivalent levels does not meet the requirements, especially when pulsed noise sources are active. The experimental technique is proposed for the response function calculation and its use in evaluating the noise conditions in rooms with noncontinuous noise sources.Practical implications: The experimental determination of the response function to pulse excitation allows studying the acoustic processes in rooms for the formation of noise conditions when analytical methods cannot be used. The experimentally obtained response function makes it possible to solve problems of changing the noise conditions in rooms with noncontinuous noise sources.

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