Electro-solid-fluid Coupling Simulation And Dynamic Modeling Of The Synthetic Jet Valveless Piezoelectric Micropump

The main content of this paper is the dynamic modeling of the synthetic jet valveless piezoelectric micropump and the multiphysic electro-solid-liquid coupling simulation.Because the characteristic scale is in the micron scale,the internal flow is not the same as the macroscopic flow,the medium in the pump is liquid,the equation of momentum and energy used in the general macroscopic movement can be applied to the microscopic fluid.Due to the enhancement of the coupling characteristics of the whole system at the micro scale,the research on the coupling characteristics of the valveless piezoelectric micropump of the synthetic jet is still in a blank state.In addition,the difficulties in dynamic modeling and experimental research also bring great challenges to the coupling research.The study of coupling simulation that involves multiphysical fields such as electric,solid and fluid can better simulate the actual working conditions of the operation of the micro pump,but simulation analysis of the synthetic jet valveless piezoelectric micropump is still in the single fluid or solid field,which cannot be able to accurately simulate the actual situation of the synthetic jet valveless piezoelectric micropump.In this paper,the synthetic jet valveless piezoelectric micropump was theoretically modeled and analyzed,and the method of fully coupled numerical simulation and experiment was combined to simulate the electro-solid-liquid coupling of the piezoelectric micropump.The research is as follows:The theory of synthetic jet is introduced in detail and the forming condition of the synthetic jet is described in detail.the flow field of the synthetic jet is analyzedThe motion of micro-fluid in valveless piezoelectric micropump is introduced,and the dimensionless number describing the motion of micro-fluid is introduced,besides,the piezoelectric effect and piezoelectric material are introduced specifically.The double layer piezoelectric actuator is simplified based on elastic thin plate theory and its dynamic model is established.The electro-solid coupling simulation of the piezoelectric vibrator is carried out.The vibration displacement experiment of the piezoelectric vibrator was performed to verify the correctness of the electro-solid coupling simulation.The dynamic modeling of the valveless piezoelectric micro-pump was carried out to obtain the internal pressure,interface velocity and natural frequency of the micropump.The professional coupling software COMSOL Multiphysics was used on the coupling simulation of the synthetic jet valveless piezoelectric micropump with multiple physical fields electro-solid-liquid coupling simulation of the synthetic jetvalveless piezoelectric micropump.The three dimensional structure of coupling smodel is established and the coupling simulation is carried out including fluid-solid coupling analysis,solid-liquid coupling analysis and two-way coupling of piezoelectric vibrator,in addition,a comprehensive analysis of the characteristics of service under the coupling effect of piezoelectric actuators and the flow characteristics of fluid flow were completed.The results of the simulation show that the maximum displacement of the suction stage is the same as the biggest displacement of discharge stage.At the same time,the formation process of the synthetic jet can be seen from the flow chart,which conforms the design concept of the synthetic jet valveleless piezoelectric micropump.Based on the simulation results,the voltage and frequency loaded on the piezoelectric vibrator must be in the fixed scope,and the synthetic jet valveless piezoelectric micropump can have heavy flow rate at the exit of the micropump,mainly because the size of the synthetic jet cavity is certain,the formation and development of vortexs need enough time and the cavity needs a certain amount of fluid,so the voltage is too large or the frequency is too low will not be able to meet the conditions.The experimental results show that the outlet flow rate of the micropump is very small no matter how the voltage changes at low frequency when frequency is constant.When the frequency increases,the flow rate first increases and then remains unchanged.When the voltage is constant,the outlet flow rate increases with the increase of frequency,but the outlet flow rate will become small again if the frequency exceeds 100 Hz,which is consistent with the results of previous coupling simulations.