Time Delay Based Noise Control in Centrifugal Fans

Abstract

The most common noise control systems are already based on passive and active techniques. Passive noise control is a typical technique for high frequency noise and active noise control also for low frequency noise. In this paper, a simple and cheap method is proposed to determine the difference between sound waves of two centrifugal fans based on time delay in power starting to control low frequency noise.

The highest level in the noise level analysis shown in study fans is at 250 Hz. In the interference stage of study, noise measurements were recorded in the time delay of 3, 6 and 8 ms for power start for one of the fans. Results showed that an 8 ms time delay resulted in 1.3 – 2.3 dB(L) reduction in total sound pressure level of fans. This method is suggested for noise control of low frequency in the same sources.

Keywords

noise control fan time delay wave interference

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References

Brain Ross

ten Wolde

Tjeert

, Noise from Traffic as a Worldwide Policy Problem, Noise Control Engineering Journal, 49(4). July-Aug 2001.

J D

Bai

M R

, Application of feed forward adaptive active-noise control for reducing blade Passing noise in centrifugal fans, Journal of Sound and Vibration 239(5), pp. 1051–1062, 2001.

Velarde-Suarez

Ballesteros-Tajadura

Hurtado-Cruz

J P

, A predictive maintenance procedure using pressure and acceleration signals from a centrifugal fan, Applied Acoustics, Volume 67, Issue 1, pp. 49–61, January 2006.

Gerard

Berry

Masson

, Control of tonal noise from subsonic axial fan, part 1: Reconstruction of aero acoustic sources from free field sound pressure, Journal of Sound and Vibration 288, pp. 1049–1075, 2005.

Elliott

S G

, “Signal processing for active noise control”, Academic Press, 2001.

Kouan

S M

Morgan

D R

, Active Noise Control Systems Algorithms and DSP Implementation, Willy & Sons 1996.

Tokhi

M O

Leith

B R

, Active Noise Control, Clarendon Press, Oxford, 1992.

Leventhall

, A review of published research on low frequency noise and its effects, DEFRA, London. 2003.

Romeu

Saluenä

Jimeânez S

Capdevila

Coll

, Active noise control in ducts in presence of standing waves. Its influence on feedback effect, Applied Acoustics 62 3–14, 2001.

10.

Hull

A J

Radcliffe

C J

Southward

S C

, “Global Active Noise Control of a one-dimensional Acoustic Duct Using a Feedback Controller”, Journal of Dynamic systems, measurement and control, Vol 115, pp.488–494, 1993.