Active control of sound through full-sized open windows. (15th August 2018)

• Record Type: Journal Article
• Authors: Lam, Bhan; Shi, Chuang; Shi, Dongyuan; Gan, Woon-Seng
• Is Part Of: Building and environment. Volume 141(2018)
• Page Start: 16
• Page End: 27
• Publication Date: 2018-08-15
• Subjects: Active noise control -- Finite element method -- Noise mitigation through open windows -- Building acoustics; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2018.05.042
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: There is a pressing need to address urban sustainability challenges of increasing ambient temperatures and noise levels in densely-populated, high-rise cities. Solutions that utilise active noise control on open windows to reduce indoor noise levels seem promising, as natural ventilation is still maintained. Active noise control utilizes acoustic transducers arranged around the open window to generate a secondary incidence noise that destructively interferes with the real noise. The two most common techniques of transducer arrangement, distributed and boundary layouts, are investigated for the typical single-glazed sliding window. Finite element method is used to establish the control performance of the active noise control system and the passive attenuation provided by the sliding window. Based on the investigated fundamental limits of active control, the distributed layout has consistently yielded better performance than the boundary layout. The distributed-layout method can also reduce noise more effectively than a fully-glazed window. Moreover, sources distributed only in the partial opening of a simulated sliding window can attenuate noise as effectively as the fully-glazed window. The distributed-layout method is tested on a full-sized window, where the active control system has up to 16 channels and evenly distributed across the window opening. In the test with tonal sounds, the feasibility of the active control system is demonstrated. The experimental results have validated the simulation findings for normal incidence plane waves. Highlights: Theoretically, active control shields noise better than a fully-glazed aperture. Control sources distributed across the aperture outperform the boundary layout. Sources distributed in the sliding window opening provides sufficient shielding. In experiments, the active control performance approaches full-glazing insulation.