基于声黑洞设计理论的径向夹心式径-弯复合换能器  

Radial sandwich radial-bending composite transducer designed based on acoustic black hole theory

作　　者：刘洋[1] 陈诚 林书玉[1] Liu Yang;Chen Cheng;Lin Shu-Yu(Shaanxi Key Laboratory of Ultrasonics,School of Physics and Information Technology,Shaanxi Normal University,Xi’an 710119,China)

机构地区：[1]陕西师范大学物理学与信息技术学院,陕西省超声重点实验室,西安710119

出　　处：《物理学报》2024年第8期159-168,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12174240,11674206,11874253)资助的课题.

摘　　要：基于弯曲波在声黑洞(acoustic black hole,ABH)结构中振幅不断增大的特性,提出了一种新型径向夹心式径-弯复合换能器,该换能器由径向夹心式圆环换能器与外围的环形ABH结构组成.ABH结构的存在实现了换能器径向振动与弯曲振动之间的转换,提高了换能器的声辐射性能.利用几何声学的方法建立了ABH结构弯曲振动的解析模型,给出了其弯曲振动的本征频率,并结合有限元方法讨论了换能器机电转换性能随尺寸变化的关系.通过有限元方法给出了该换能器在空气中的辐射声压场、辐射声强以及辐射指向性,仿真结果表明,ABH结构的存在能够改善换能器弯曲振动的机电转换性能,提高换能器的声辐射性能,使换能器呈现出一定的辐射指向性.最后通过实验对换能器样机的电阻抗特性以及振动模态进行测量,实验结果与仿真相符合.A novel radial sandwich radial bending composite transducer is proposed based on the increasing amplitude of bending waves in the structure of an acoustic black hole(ABH).The transducer consists of a radial sandwich circular ring transducer and an outer acoustic black hole structure.The existence of the ABH structure realizes the conversion between radial vibration and bending vibration of the transducer,and improves the acoustic radiation performance of the transducer.Based on the one-dimensional acoustic black hole bending vibration theory,the bending vibration equation of the circular ABH structure is given.An analytical model of the ABH structure bending vibration is established by using the method of geometrical-acoustics,and the eigen frequency of its bending vibration is given.The relationship between the electromechanical conversion performance and the size of the transducer is discussed by using the finite element method,and the results show that when the eigen frequency of the bending vibration of the ABH structure is close to the resonant frequency of the transducer,the electromechanical coupling coefficient of the transducer reaches a maximum value.The radiation sound pressure field,radiation sound intensity,and radiation directionality of the transducer in the air are also analyzed by the finite element method.The results indicate that the presence of the ABH structure can improve the electromechanical conversion performance of the bending vibration of the transducer,enhance the acoustic radiation performance of the transducer,make the transducer exhibit radiation directionality and the lower order of the bending vibration mode of the ABH structure,the stronger radiation directionality of the transducer towards the left side and the right side.Finally,in order to verify the accuracy of the simulation and theory,we made a prototype transducer and carried out the experimental test of transducer electrical impedance and vibration mode.The measured results are in good agreement with the simulation result

关 键 词：声黑洞 换能器 径向振动 弯曲振动 

分 类 号：TB552[理学—物理]