压电式微型合成射流器结构参数优化设计

Structural Parameters Optimization of Piezoelectric Micro Synthetic Jet Actuators

压电式微型合成射流器的结构参数对射流速度有极大影响,然而各结构参数的影响规律及程度无法用单因素考查法来确定。针对这个问题,采用正交分析法结合多域耦合数值模拟,研究了主要结构参数对射流速度的综合影响,对器件结构参数进行了优化。仿真结果表明:在所考查的参数范围内,喷口宽度、腔体宽度、压电片厚度对射流速度的影响较大,但三者的影响程度依次降低;射流速度随喷口宽度、压电片厚度的增大而减小,随腔体宽度的增大而增大;压电片宽度对射流速度影响很小。在此基础上,采用微机电系统(MEMS)加工工艺制作了压电式微型合成射流器,测得器件能承受的最大激励电压为30 V,最大射流速度为10 m/s,最佳工作频率为10 kHz。

The orthogonal method and multiple-domain coupling numerical simulation are used to explore the influence of structural parameters on piezoelectric micro synthetic jet velocity. As a precondition the orifice thickness, chamber height and diaphragm thickness are predefined for the sake of micromachining economy. The results show that the orifice width, chamber width and PbZr,Ti1-xO3 （PZT） thickness affect the jet velocity seriously. In the range of the test, the jet velocity decreases with increasing orifice width and PZT thickness, or with decreasing chamber width. The PZT width has the least influence on the jet velocity. The research is valuable for structural design optimization of piezoelectric micro synthetic jet actuators. Finally, piezoelectric micro synthetic jet actuators are fabricated with Si micromachining technology based on the above study. Peak jet velocity of 10 m/s is obtained with 30 V and 10 kHz AC electric drive.