title: Acoustic performance of boundaries having constant phase gradient.
abstract: In this paper, inhomogeneous boundaries having constant phase gradient are investigated. In principle, such a theoretically proposed boundary is dispersionless. In practice, however, when the boundary is realized by a subwavelength-structured tubes array, the impedance discretization brings about sub-reflections at high frequencies. Moreover, determined by the longest duct in the array, a realized boundary is impractically thick. Therefore, a finite-thickness boundary is further proposed by truncating and periodizing the tubes in the array. In this paper, the theoretical analysis agrees well with the numerical simulations. By appropriately choosing its phase gradient and target frequency, the finite-thickness boundaries have potential applications in noise control.
authors.affiliation: Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Shanghai Academy of Environmental Sciences, No. 508 Qingzhou Road, Shanghai 200233, China xuwang@tongji.edu.cn, wangxn@saes.sh.cn, ywzh@tongji.edu.cn, zxjiang@tongji.edu.cn, dxmao@tongji.edu.cn.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China.
authors.forename: Wuzhou
authors.initials: W
authors.lastname: Yu
authors.affiliation: Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China.
authors.forename: Zaixiu
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Institute of Acoustics, Tongji University, No.1239 Siping Road, Shanghai 200092, China.
authors.forename: Dongxing
authors.initials: D
authors.lastname: Mao