Active and passive noise control in practice on the Saab 2000 high speed turboprop

1998 ◽  
Author(s):  
Urban Emborg ◽  
Fredrik Samuelsson ◽  
Joakim Holmgren ◽  
Siv Leth
Keyword(s):  
High Speed ◽  
Noise Control ◽  
Passive Noise

A Critical Review of Passive Noise Control Techniques in Industrial Fans

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
Stefano Bianchi ◽  
Alessandro Corsini ◽  
A.G. Sheard
Keyword(s):  
High Speed ◽  
Noise Control ◽  
Theoretical Research ◽  
Future Research ◽  
Fan Noise ◽  
Acoustic Effect ◽  
Control Techniques ◽  
Current State ◽  
Control Technologies ◽  
Passive Noise

This review aims to assist engineers in understanding and applying passive solutions for reducing industrial fan noise. The paper systematically reviews the extant literature on passive noise techniques, with a particular focus on experimental rather than theoretical research. The review provides an assessment of the current state of the art in industrial fan flow and noise control. It offers a vision for potential improvements in noise reduction via novel application of flow and noise control technologies. The review examines the interaction between aerodynamic cause and acoustic effect and the application of control technologies that current cause and effect theories have inspired. The purpose is to provide a vision for aerodynamics research during the next decade that will serve as a basis for systematically reducing industrial fan noise emissions. The review provides an assessment of recent flow and noise control advances and considers some opportunities for future research. The review reflects an emphasis on low-speed industrial fans. The authors consider high-speed turbomachinery noise control, with the objective of illustrating the linkages between the two technologies. The review concludes with a summary of the opportunities for future research and its application to flow and noise control in industrial fan design.

Active Helmholtz Resonator With Positive Real Impedance

2006 ◽  
Vol 129 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Jing Yuan
Keyword(s):  
Noise Control ◽  
Helmholtz Resonator ◽  
Control Device ◽  
Positive Real ◽  
Noise Field ◽  
Strictly Positive Real ◽  
Control Devices ◽  
Passive Noise ◽  
Active Resonator ◽  
Electronic Resonance

The impedance of a passive noise control device is strictly positive real, if the device is installed in noise fields with weak mean flows. Passive noise control devices are, therefore, more reliable than active ones. Active control may be applied to a Helmholtz resonator to introduce electronic resonance. It will affect the impedance Zact of the resonator. A controller may be designed such that (a) Zact is small and resistive at some tunable frequencies; and (b) Re{Zact}⩾0 in the entire frequency range of interest. If criterion (a) is satisfied, the active resonator can suppress duct noise at tunable frequencies. It is difficult to design a controller to satisfy criterion (b) because parameters of the controller depend on acoustic parameters of the noise field. A new method is proposed here to design an active controller to meet both criteria simultaneously. The satisfaction of criterion (b) implies a positive real Zact and a robust active resonator with respect to parameter variation in the noise field. Experimental results are presented to verify the performance of the active resonator.

Hybrid active and passive noise control in ventilation duct with internally placed microphones module

2022 ◽  
Vol 188 ◽  
pp. 108525
Author(s):  
Lifu Wu ◽  
Lei Wang ◽  
Shuaiheng Sun ◽  
Xinnian Sun
Keyword(s):  
Noise Control ◽  
Passive Noise ◽  
Ventilation Duct

A Review of Active Noise Control Applications on Noise Barrier in Three-Dimensional/Open Space: Myths and Challenges

2019 ◽  
Vol 18 (04) ◽  
pp. 1930002 ◽  
Author(s):  
Hsiao Mun Lee ◽  
Zhaomeng Wang ◽  
Kian Meng Lim ◽  
Heow Pueh Lee
Keyword(s):  
Open Space ◽  
Noise Control ◽  
Active Noise Control ◽  
Three Dimensional ◽  
Construction Site ◽  
Noise Sources ◽  
Current State ◽  
Active Noise ◽  
Noise Barrier ◽  
Passive Noise

Active noise control (ANC), with counteracting sound in exact equal magnitude and opposite phase to the noise to be controlled, is often considered as a potential solution for solving complex noise problems. However, there are both myths and challenges in its implementations. In a crowded city like Singapore, many noise sources from construction site and subway track are located very close to the residential and commercial buildings. It was suggested by few researchers that by placing suitable control speakers at the construction site (working principle of ANC), the noise from the construction site could be prevented from propagating to the surrounding buildings. Similarly, for viaduct or subway track, by placing control speakers along the viaduct or track, the noise generated by the passing trains or vehicles could be reduced based on the principle of ANC technique. However, implementation of ANC technique on these noise issues is not easy as all of these noise control problems involve multiple noise sources with complex or transient frequency spectrum in large three-dimensional/open space. Therefore, the main intention of the present paper is to discuss the current state of the art of this topic as well as to examine the potential application and limitation of the ANC technique in mitigating unwanted noise, particularly in large three-dimensional/open space and with cooperation of passive noise barrier.

Active and passive noise control using electroactive polymer actuators (EAPAs)

1999 ◽  
Author(s):  
Kartik Ramanathan ◽  
Bei Zhu ◽  
Woosuk Chang ◽  
Vasundara V. Varadan ◽  
Vijay K. Varadan
Keyword(s):  
Noise Control ◽  
Electroactive Polymer ◽  
Polymer Actuators ◽  
Passive Noise
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