Miss Xue HAN, a 2nd year PhD student, made a presentation at the Acoustics 2023 Sydney, 2-8 Dec (Annual Conference of the Acoustical Society of America, joint with the Acoustical Society of Australia) and received a Student and Early Career Best Paper Award from the Acoustical Society of America Noise Technical Committee.
Paper title: Broadband noise absorption by time-varying devices
Authors: Xue Han, Ying Hu, Xiaocong Zhu, and Lixi Huang
1. Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China
2. School of Mechanical Engineering, Zhejiang University, Hangzhou, China
Abstract: A resonator array can broaden the effective sound absorption bandwidth by using the structure with multiple cavities in parallel or in series in space. However, this kind of fixed mechanical structure cannot flexibly adapt to different noise sources, which severely limits the development prospect of the resonator array in practical applications. In this paper, a time-varying resonator is proposed based on a shunted electrical circuit, realizing the equivalent effect of multi-cavities in space. Based on the working principle of spatial and temporal resonators, the theoretical models are established, and the three designs for achieving broadband effects are analyzed theoretically. Through time-domain numerical calculation, the sound absorption performance of the two spatial designs and the temporal design with the same cavity volume is obtained. This study focuses on the scheme design and performance optimization of the temporal resonator. Compared with the traditional spatial resonator, the proposed temporal resonator has the advantages of tunable frequency and high adaptability to varying sources while achieving similar or even better sound absorption performance.