阶梯盘超声辐射声场指向性研究

The Study of Radiated Acoustic Field Directivity of Stepped Circular Plate

指向性是衡量声源性能的重要参数。本文中研究了阶梯盘指向性与阶梯数目之间的关系。设计了频率和基底厚度一定的1~4阶阶梯盘。计算了4个阶梯盘以及与阶梯盘对应的同频率、同半径的活塞盘的指向性。结果表明,阶梯盘与和它同频率同半径的活塞盘的指向性主瓣同,但前者的旁瓣比后者多。频率、基底厚度一定时,阶梯数目越多(对应的半径也越大),指向性也越尖锐。实验测试与理论计算结果相符。

The directivity is an important parameter for measuring the performance of the sound source. In order to study the relationship between directivity and the number of steps of stepped plate,four plates with one to four steps of the same frequency and base thickness are designed in this paper. The directivity of four stepped plates and the piston plates which have the same frequency and thickness with those four stepped plates are calculated. The result shows that,the stepped plates have the same main lobe as the piston plates,but the side lobes of the former are more than those of the later. For the given frequency and base thickness,with the increasing of the number of the steps（ it means the plate with greater radius）,the directivity is sharper; the experiment of fabricated stepped plates shows that the experimental results are in good agreement with the calculated ones.