压电微流体泵液-固耦合系统流动特性

Flow behavior of liquid-solid coupled system of piezoelectric micro-pump

该文采用厚度积分平均的浅水模型和有限元法,得到压电微流体泵液体-硅振动片动力耦合振动方程。液-固耦合系统的模态分析给出硅片一阶模态自然频率和振型,以及硅片振幅-频率关系曲线。在模态分析基础上,加入压电效应,计算压电-硅片在外加电场作用下的振动响应。文中采用有限体积法计算微流体泵周期流动,得到微泵流量-频率的特征曲线,以及泵腔周期流动规特征。数值结果表明,在给定外加电压时,可以确定一个使微泵流量最大的工作频率。

This paper employs an integral-averaged shallow water model and a finite element method to approximate periodical flows in a piezoelectric micro-pump. A liquid-solid coupled system equation of the silicon diaphragm is presented. The mode analysis of liquid-solid coupled system yields the first order natural frequency, vibration shape and the diaphragm amplitude-frequency relationship. The vibration response of the silicon diaphragm is calculated when external electric field is applied. Based on the integral-averaged flow equation the periodical flow of the micro-pump is studied using finite volume method to obtain the flow rate-frequency characteristics and flow behavior. Numerical results indicate that a working frequency can be found, at which the flow rate of the micro-pump is maximum when external electric voltage is fixed.