2024-03-28T17:44:44Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/217382010-02-28T23:00:00Zcom_10261_32com_10261_4col_10261_285
Hybrid passive–active absorption using microperforated panels
Cobo, Pedro
Pfretzschner, Jaime
Cuesta, María
Anthony, David K.
Architectural acoustics
Acoustic wave absorption
Active noise control
Impedance matching
Acoustic impedance
8 pages.-- PACS: 43.55.Ev; 43.50.Ki
A theoretical and experimental study of a proposed hybrid passive–active plane-wave system to provide broadband acoustic absorption is presented. The passive absorber consists of a microperforated panel (MPP), used in place of conventional fibrous materials, in front of an air layer. The active system uses an active transducer (a loudspeaker), an error sensor (a microphone), and an adaptive controller. MPPs are thinner than fibrous materials and provide a better solution in hygienic environments. For two such systems, the dependence of performance on MPP parameters is studied for two control strategies: impedance matching and pressure release. The first condition is found to be better for cases where the acoustic impedance of the system approaches that of air. Otherwise, the pressure-release condition is better, and a wideband solution is the implementation of the active control system up to a frequency where the natural band of the passive system provides higher absorption. Therefore, the use of a low-pass filter in the error signal is implemented to afford hybrid passive–active wideband absorption. The control effort of active system is also considered. Experimental verification shows good agreement with theory, and an average absorption coefficient of 0.82 in the frequency bandwidth 100 to 1600 Hz was achieved.
2010-03-01T09:41:15Z
2010-03-01T09:41:15Z
2004-10
artículo
Journal Acoustical Society of America 116(4): 2118-2125 (2004)
0001-4966
http://hdl.handle.net/10261/21738
10.1121/1.1786831
eng
http://dx.doi.org/10.1121/1.1786831
closedAccess
Acoustical Society of America