宽频可调声非对称传输器件设计

Tunable broadband asymmetric acoustic transmission device

频带窄和结构复杂是现有非对称传输声学器件设计中的主要问题。设计了一种声学超表面弯管结构非对称传输声学器件,该器件在6000～8500Hz频带的宽频范围内实现了正向导通而反向截止的声单向传输特性。透射型超表面单元结构与背景介质良好的阻抗匹配使得该声单向器件在导通时具有较高的透射效率。通过调节弯管倾斜角度得到了效率较高的单向传输设计方案。同时,通过调节透射型超表面的旋转角度,实现了双向隔声性能,并研究了双向隔声的控制规律。该设计为声波非对称传输提供了一种简单的实现方法,在宽频噪声控制和超声医学等领域都具有潜在的应用价值。

Narrow bandwidth and complicated structure are the key drawbacks for existing asymmetric acoustic transmission devices.A unidirectional acoustic transmission device composed of bended tubes and two different kinds of acoustic metasurfaces is proposed in this paper.One-way acoustic transmission is realized in the bandwidth from6000Hz to8500Hz.The properties of the unidirectional acoustic transmission are implemented by the anomalous reflection and refraction with acoustic metasurfaces.The relatively high transmission efficiency of the one-way device is realized by the impedance matching between the inert gases filled in the acoustic metasurface elements and air as the background medium.A more efficient one-way transmission design is obtained by adjusting the elbow angle.Additionally,two-way acoustic insulation can come true by rotating the refractive acoustic metasurface automatically.Appropriate strategies are generated to satisfy different needs for two-way insulation with acoustic metasurfaces.Our work provides a simple method of designing a broadband unidirectional acoustic transmission device and has potential applications in many fields such as noise control,medical ultrasound and imaging.