超声换能器表面振动和声场测量及其与经典超声换能器的仿真比较

超声换能器广泛应用于声学测量,其工作性能主要取决于它的振动与声特征。然而,多数研究中的换能器被认为是经典的活塞或高斯型,经典与常用的真实换能器之间的差异容易被忽视。基于此,首先用激光测振和传声器测声方法测量了某厂家换能器产品的表面振动与声场特征。然后设计有限元方案,分别仿真经典与真实换能器的声场。最后从辐射面振速分布、声场声压和相关系数等方面,综合比较经典与真实超声换能器之间振动与声场的异同。结果表明,换能器间的辐射面振速分布差别明显,所研究的真实换能器的声场特征接近于活塞,而与高斯型差别较大。

Surface vibration and acoustic field measurements of real ultrasonic transducer and its comparison with classic one

The ultrasonic transducers are widely used in acoustic measurements, and their working performance mainly depends on their vibration and acoustic characteristics. In most researches, the transducer is considered as the classic Piston or Gaussian one, but the difference between the real transducer and the classic one is usually ignored. In this paper, the surface vibration and acoustic field of a real made transducer are measured firstly by using laser vibration meter and microphone, and then a finite element scheme is designed to simulate the acoustic fields of the classic and the real transducers. Finally, the differences and similarities between classic and real transducers are analyzed in the three aspects:velocity distribution on radiation surface, pressure along acoustic axis and correlation coefficients. The results show that the velocity distributions on radiation surface are different between these transducers, the acoustic field characteristics of the real transducer are close to the Piston one, but greatly different from the Gaussian one.