Active control of drag noise from a small axial flow fan

Wang, Jingbo; Huang, Lixi

doi:10.1121/1.2204443

Cited by 12 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The motivation for the work presented in this paper is connected with previous work investigating the active control of small axial cooling fans, which can be characterized as compact acoustic sources. Active noise control of axial cooling fans has been studied using various control source configurations [1][2][3][4][5][6][7][8] . The range of control system configurations includes simple single control source configurations [1][2][3] to four control sources in various configurations [5][6][7] .…”

Section: Introductionmentioning

confidence: 99%

Characterization of microphone placement and noise sensitivity in a global active noise control system for a compact noise source

Rust¹,

Sommerfeldt²,

Gee³

et al. 2013

noise cont engng j

View full text Add to dashboard Cite

This paper presents a sensitivity analysis to error microphone placement and extraneous noise sources for two control source configurations used for the active control of noise radiated from a compact source. The two control configurations analyzed are a linear array of four control sources with the primary source in the middle of the array and a symmetric array of four control sources surrounding the primary source. For modeling purposes, the primary source and the control sources are modeled as simple sources with a baffled free space Green's function to predict the noise measured by the four error microphones. The control source strengths which minimize the squared pressure at the error microphones are solved for based on error microphone locations. If the microphones are placed properly with no error in spatial location, this minimization process has been previously shown to result in radiated power minimization. Simulation results show the linear array is significantly more sensitive to microphone placement errors than the symmetric array. The linear array configuration is also shown to be more sensitive to added random noise in the error signals. Experimental results suggest that for the configurations used, the sensitivity to microphone placement errors was the dominant effect. The reduction in performance for the linear array configuration is significant with microphone placement errors and/or added random noise, while the reduction in performance for the symmetric array is minimal.

show abstract

Section: Introductionmentioning

confidence: 99%

Characterization of microphone placement and noise sensitivity in a global active noise control system for a compact noise source

Rust¹,

Sommerfeldt²,

Gee³

et al. 2013

noise cont engng j

View full text Add to dashboard Cite

show abstract

“…When higher order modes propagate in the duct, more loudspeakers are required to control all the propagating modes. Recently, studies have been carried out to actively control the tonal noise radiated by the exhaust fans [2], computer fans [3,4], or engine cooling fans [5,6]. The directivity of the fan noise radiation must be taken into account to efficiently control the sound in the whole space.…”

Section: Introductionmentioning

confidence: 99%

A Compact Active Control System for Tonal Noise Reduction in Axial Fans

Gérard

Berry

Masson

2007

Noise & Vibration Worldwide

View full text Add to dashboard Cite

The objective of this paper is to show the feasibility of active control of tonal noise from automotive engine cooling fans using a single unbaffled loudspeaker in front of the fan. A simplified model is described for preliminary design using this configuration. A single input single output (SISO) filtered X-LMS has been implemented to control the first tones in real time. At the error microphone, the sound pressure attenuation at blade passage frequency (BPF) and its first harmonics are reduced down to the broadband noise level. At low frequency, for large sound wavelength compared to the fan radius, the sound radiation is reduced in all directions, since the dipolar directivity of the secondary noise emitted by the unbaffled loudspeaker is similar to the directivity of the primary noise emitted by the fan.

show abstract

“…Although active control is a possible option (e.g., Wang et al, 2005;Wang and Huang, 2006), the need of the a) Author to whom correspondence should be addressed. Electronic mail:…”

Section: Introductionmentioning

confidence: 99%

Noise suppression of a dipole source by tensioned membrane with side-branch cavities

Liu

Choy

Huang³

et al. 2012

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Reducing the ducted-fan noise at the low frequency range remains a big technical challenge. This study presents a passive approach to directly suppress the dipole sound radiation from an axial-flow fan housed by a tensioned membrane with cavity backing. The method aims at achieving control of low frequency noise with an appreciable bandwidth. The use of the membrane not only eliminates the aerodynamic loss of flow, but also provides flexibility in controlling the range of the stopband with high insertion loss by varying its tension and mass. A three-dimensional model is presented which allows the performance of the proposed device to be explored analytically. With the proper design, this device can achieve a noise reduction of 5 dB higher than the empty expansion cavity recently proposed by Huang et al. [J. Acoust. Soc. Am. 128, 152-163 (2010)]. Through the detailed modal analysis, even in vacuo modes of the membrane vibration are found to play an important role in the suppression of sound radiation from the dipole source. Experimental validation is conducted with a loudspeaker as the dipole source and good agreement between the predicted and measured insertion loss is achieved.

show abstract

Active control of drag noise from a small axial flow fan

Cited by 12 publications

References 18 publications

Characterization of microphone placement and noise sensitivity in a global active noise control system for a compact noise source

Characterization of microphone placement and noise sensitivity in a global active noise control system for a compact noise source

A Compact Active Control System for Tonal Noise Reduction in Axial Fans

Noise suppression of a dipole source by tensioned membrane with side-branch cavities

Contact Info

Product

Resources

About