Optimization of single-channel active noise control performance in a plenum window using the surface impedance approach.

The use of active noise control (ANC) implementation in plenum window design is investigated in this study. Various simulated configuration of a single-channel ANC is performed using the surface impedance approach (SIA) in order to optimize ANC performance. Based on a systematic search procedure, the optimal control source placement is found for a control source localized at the central bottom and central depth of the plenum window, near the window's inlet from which primary noise is impinging.

Modeling of multiply connected sound spaces by the surface coupling approach.

The surface coupling approach is employed to predict the sound field in multiply connected spaces (rooms) with internal noise sources. The coupling is achieved by developing sound pressure and particle velocity at the interfaces between rooms in simple interface functions. Plane surface harmonics can be employed as interface functions where rectangular interfaces are concerned.

Experimental study on sound transmission loss of plenum windows.

To investigate the noise reduction mechanism of plenum windows, the paper experimentally studied the influence of the air-gap spacing between two glass panes, the panel thickness, and the opening size on the sound transmission loss (TL). The results show that when the half wavelength of impinged sound is smaller than the air-gap spacing, the TL can be improved by the decrement of the opening sizes and the increment of the glass thickness but varies little with changes in air-gap spacing. When the half wavelength of impinged sound is larger, the modification of the three factors makes little impact on the TL.