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第 39 卷 第 6 期                                                                       Vol. 39, No. 6
             2020 年 11 月                         Journal of Applied Acoustics                 November, 2020

             ⋄ 2019年度全国检测声学和第10届全国储层声学与深部钻测技术前沿联合会议优秀论文 ⋄



                             平面超薄准直器件的参数依赖性                                               ∗




                                                   胡 洁     †   王昊泽


                                            (南京林业大学信息科学技术学院         南京   210037)

                摘要：该文设计了一具有高效强指向性的平面超薄人工结构，当平面声波垂直入射到该结构时，若中心狭缝处
                产生的 Fabry-Perot(F-P) 共振和两侧类亥姆霍兹凹槽的共振频率耦合时，会产生一具有高度指向性的准直声
                束。通过对结构两侧的凹槽阵列的作用、凹槽周期 D 和凹槽数量 r 的探讨，发现凹槽阵列可将散射声波转换成
                声表面波，大大提高了透射效率，同时结构的共振频率、声透射率和准直效果与 D、r 的变化关系不大，说明对
                该结构准直效应产生影响的是 F-P 共振频率和类亥姆霍兹共振器共振频率，与布拉格散射无关。这一发现有
                助于在降低结构尺寸的同时仍保持结构的有效性，为后续指向性器件的应用提供了理论依据。
                关键词：高指向性；人工结构；F-P 共振；类亥姆霍兹共振器
                中图法分类号: O424           文献标识码: A          文章编号: 1000-310X(2020)06-0799-05
                DOI: 10.11684/j.issn.1000-310X.2020.06.001



                            Parameter dependence of thin planar collimating device



                                                  HU Jie WANG Haoze

                       (College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China)

                 Abstract: A high-efficiency collimation of acoustic waves through an ultra-thin planar structure is designed in
                 this paper. When incident plane waves propagate into the structure vertically, a high collimated acoustic beam
                 is generated as the Fabry-Perot (F-P) resonance in the aperture is coupled with the bilateral Helmholtz-like
                 resonators. We investigate the design principle of the Helmholtz-like grooves, as well as the dependence of
                 transmission efficiency and far-field directivity on the period of the Helmholtz-like array, D, and the number of
                 the grooves, r. The results show that the grooves convert the scattered waves into the acoustic surface waves to
                 improve the transmission efficiency greatly. And the change of D and r has not much influence on the resonant
                 frequency, transmission coefficient and directivity significantly, so that the collimation functionality is related
                 to the coupling between F-P and Helmholtz-like resonances instead of Bragg scattering. This may contribute to
                 downscale the collimation device without decreasing the efficiency of the structure, which provides theoretical
                 basis for further application of collimating devices.
                 Keywords: High collimation; Artificial structure; F-P resonance; Helmoholtz-like resonator









             2020-06-28 收稿; 2020-09-11 定稿
             国家自然科学基金项目 (11804162)
             ∗
             作者简介: 胡洁 (1980– ), 女, 江苏宜兴人, 博士, 讲师, 研究方向: 声信号处理。
             † 通信作者 E-mail: hujie@njfu.edu.cn
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