title: Modeling, analysis, and validation of an active T-shaped noise barrier.
abstract: With ever-increasing land traffic, abatement of traffic noise using noise barriers remains significant, yet it is a challenging task due to spatial competition with other infrastructure. In this study, a deep insight into the diffraction characteristics of acoustic fields near noise barriers of various geometries and surface conditions was achieved using numerical simulations. A T-shaped passive noise barrier with acoustically soft upper surfaces was demonstrated to outperform other candidates in a middle- or high-frequency range. Based on attributes of the acoustic field diffracted by T-shaped barriers, an active control strategy was developed to revamp the T-shaped barrier, in which a filtered minimax algorithm was established to drive the secondary sound sources. This algorithm resulted in more uniformly distributed residual sound fields than a filtered-X least mean square algorithm. Performance of the actively controlled barrier was evaluated at different positions and spacings of secondary sound sources and error sensors, leading to a series of optimal criteria for the design of active noise barriers. A prototype was fabricated and validated experimentally, manifesting particular effectiveness in insulating low-frequency noise, supplementing well the capacity of a passive T-shaped barrier which is effective in the middle- or high-frequency range.
authors: The Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administration Region.
authors: Rongping
authors: R
authors: Fan
authors: Zhongqing
authors: Z
authors: Su
authors: Li
authors: L
authors: Cheng
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000465:Algorithms; D003198:Computer Simulation; D004867:Equipment Design; D016018:Least-Squares Analysis; D008422:Materials Testing; D008962:Models, Theoretical; D009038:Motion; D009624:Noise, Transportation / Q000517:prevention & control*; D009716:Numerical Analysis, Computer-Assisted; D011312:Pressure; D015203:Reproducibility of Results; D013499:Surface Properties