压电振子结构参数对微雾化器耦合特性的影响

Effects of Geometry of Piezoelectric Actuator on Coupling Characteristics of Micro Nebulizer

针对微雾化器存在的多能域能量耦合问题,建立了压电微雾化器的固-液-声耦合模型,对其耦合特性进行了数值计算,并着重分析了压电振子结构参数对耦合性的影响,得到了压电振子结构参数对于系统的结构振动、声压力波特性的影响规律。结果表明,由于液体层与固体的耦合作用,压电振子振动的同时,喷孔膜也产生振动,而且两者之间存在相位关系;压电振子的结构参数直接影响结构的耦合性、谐振频率大小以及背膜与喷孔膜的相位差,并且存在最佳的直径比和厚度比。因此,微雾化器设计时只考虑压电振子的振幅是不全面的,必须同时考虑喷孔膜的振动以及与背膜的相位关系,新的设计原则可为微雾化器的优化设计提供指导依据。

To solve the energy coupling of multi-energy domains in the micro nebulizer, the piezoelectric-solid-liquid-sound coupling model of the micro nebulizer was built. The coupling characteristic was calculated numerically, the influence of the piezoelectric actuator geometry on the piezoelectric-solid-liquid-sound coupling was analyzed emphatically. The effect rule of the piezoelectric actuator geometry on the structural vibration and the pressure wave was achieved. The results show that the vibration of the nozzle film is also appearing with the piezoelectric actuator vibrating because of the coupling of the liquid layer and the solid, and there is the phase relation between them. The structural coupling, the resonant frequency, the phase differences of the back film and nozzle film are affected greatly by the geometry of the piezoelectric actuator, and there are the optimizal diameter ratio and thickness ratio between piezoelectric ceramic and back film. Therefore, only considering the amplitude of the piezoelectric vibration for the design of the micro nebulizer is not comprehensive, the nozzle film vibration and the phase relation between back film and the nozzle film must be considered simultaneously, and which can provide an important guidance for the optimal design of micro nebulizers.