纵振驱动球面弯曲振动超声聚焦系统的聚焦特性

Sonic focusing properties of ultrasonic focusing system based on longitudinal vibration driving spherical bending vibration

为了将超声聚焦效应应用于工业加工中的冷却技术中,该文提出一种由夹心式换能器纵向振动驱动球面弯曲振动超声聚焦系统。基于基尔霍夫-亥姆霍兹声场理论分析了由换能器中心面纵向振动和球面弯曲振动组成的复合超声振动条件下的声场聚焦特性,并通过实验进行验证。研究结果表明,该聚焦系统具有显著的聚焦特性,球面弯曲振动将声能汇聚在声场焦区;当声场相位相同时,换能器中心面纵向振动和球面弯曲振动产生的声场在焦区发生叠加,可以进一步提高焦区声压;减小换能器中心面半径和球面曲率半径、增加球面开口半径可以增强复合超声振动的聚焦效果。

In order to apply the ultrasonic focusing effect to the cooling technology in industrial processing,the ultrasonic vibrating spherical focusing system based on sandwiched transducer longitudinal vibration driving spherical bending vibration is proposed in this paper. According to the Helmholtz-Kirchhoff theory, the sonic focusing properties of the ultrasonic compound vibration which is composed of the spherical bending vibration and the longitudinal vibration of the transducer's front end plane are analyzed theoretically and verified experimentally. The results show that the acoustic radiation field of the ultrasonic compound vibration is of good sonic focusing property. The spherical bending vibration focuses acoustic energy in the focal region. What's more, the longitudinal vibration of the transducer's front end plane could further improve the acoustic energy. The decrease of the curvature radius of the bending vibrating spherical shell or the radius of the transducer's front end plane or the increase of the mouth radius of the bending vibrating spherical shell could improve the sonic focusing properties of the ultrasonic vibrating spherical focusing system.