摘要
可调频声衬结构可以实现对不同频率噪声的有效控制。该文提出了一种锥形腔体声衬结构,通过平面波理论构建锥形腔体声学的数学模型,推导了锥形腔体声衬的传递损失计算方法。将压电振子作为声衬腔体的背板,通过施加直流电压使压电振子发生形变从而改变声衬腔体的体积,达到扩大敏感频率范围的目的。结合压电振子实验所得体积变化量,采用LMS Virtual.Lab声学有限元软件对声衬模型进行声学仿真。针对直径30mm的压电振子,高为1mm的锥形声衬,当电压从0提升至500V时,体积变化量为24.1%,频率偏移量达到123Hz,频率变化百分比为13.9%,对比相同尺寸的圆柱形声衬,在相同电压变化下体积变化量为16.95%,频率偏移量为69Hz,变化百分比约为9.3%。结果表明,锥形腔体声衬比圆柱形腔体在相同直流电压作用下具有更大的频率偏移范围,可以实现噪声的变频控制。
The tunable acoustic lining structure can effectively control the noise at different frequency.A kind of conical lining structure is presented in this paper,the mathematical model of the conical cavity is established through the plane wave theory,and the transmission loss computing method of the conical cavity is derived.The piezoelectric vibrator is used as the back plate of the acoustic lining cavity,and it is deformed by applying the DC voltage to change the volume of the acoustic lining cavity,thereby achieving the purpose of expanding the sensitive frequency range.The LMS Virtual Lab acoustic finite element software is used to simulate the acoustic liners model combined with the volume change of the piezoelectric vibrator.For the piezoelectric oscillator with a diameter of30 mm and a height of 1 mm of conical sound lining,the volume change is 24.1%,the frequency offset reaches 123 Hz,and the frequency change percentage is 13.9% when the voltage is raised from 0 to 500 V.While for the same size of the cylindrical sound lining,the volume change is 16.95%,the frequency offset is 69 Hz,and the percentage change is about 9.3%in the condition of the same voltage changes.The results show that the frequency offset range of the conical cavity is larger than that of the cylindrical cavity,and can realize the frequency conversion control of the noise.
出处
《压电与声光》
CAS
CSCD
北大核心
2018年第1期138-143,共6页
Piezoelectrics & Acoustooptics
基金
国家青年科学基金资助项目(51305409)
山西省青年科技研究基金资助项目(2013021020-2)
山西省131工程领军人才支持计划基金资助项目
山西省高等学校优秀青年学术带头人支持计划基金资助项目
关键词
锥形声衬
逆压电效应
平面波理论
传递损失
共振频率
传递矩阵
conical liner
inverse piezoelectric effect
plane wave theory
transmission loss
resonance frequen cy
transfer matrix
