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On the study of the directional active attenuation of noise in free field

โœ Scribed by Jiluo Zhou; Weiming Liu

Publisher
Elsevier Science
Year
1992
Tongue
English
Weight
777 KB
Volume
37
Category
Article
ISSN
0003-682X

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โœฆ Synopsis

A BSTRA CT

On the basis of interference theory relating to two spherical sound waves with opposite phase, a mathematical model of the active sound attenuation in free field is established. A t the same time, the attenuation and the attenuated sound field are modelled. The function of the monopole system for directional active attenuation of noise in a stipulated free field can then be affirmed. The influence of the phase and amplitude errors of secondary waves on the sound attenuation are also simulated and discussed. In the discussion stress is laid on the influence of the phase error, which leads to a great reduction of the system capacity. Two types of active monopole system, the phase-shift monopole and time-delay monopole systems, are studied. Test results show suitable applications of these systems. They can be used for noise attenuation in a stipulated field, and are effective in practice.

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