Research On Traveling Wave Piezoelectric Fluid Actuators

Bas ed on the development of high-frequency driving technology of revers e piezoelectric effect,valveless piezoelectric pump has been deeply studied and applied.In foreign countries,there are many achievements in the research of valveless piezoelectric pump.However,the piezoelectric pump w ithout extern al actuator and bidirectional drive is on the rise.As a newly propos ed dynamic valveless piezoelectric pump structure,traveling wave valveless piezoelectric pump uses the pump chamber boundary as the actuating element exc ite in the boundary fixed standing wave in the superimposed way to drive the fluid in the form of traveling wave.T his structure has simplified structure and bi-directional drive function value.This paper presents a clear structure of this advantage,the main contents are summarized as follows:1.In this paper,the valveless piezoelectric pump with infinitely extended flow and small flow pulsation is proposed and the des ign idea of the piezoelectric vibrator for pump is given.The principle of generating a standing wave in the pumping cavity and forming a traveling wave pressure flow in the direction of the flow channel in the pump cavity to drive the liquid is described.2.The finite element analys is s oftware ANSYS s imulation is us ed to s imulate the natural mode of the piezoelectric vibrator.The natural modes and the corresponding frequenc ies of the piezoelectric vibrator are analyzed.The third,fourth and fifth order working modes are obtained,and take the s implest third order for example,the modal analys is and harmonic respons e analys is of the complete piezoelectric vibrator are carried out,and the approximate frequency range of the vibrator in each working mode is determined.3.Third-order,fourth-order and fifth-order prototypes were des igned and manufactured.The Doppler laser vibration meas urement system was used to conduct the frequency sweep and frequency experiment on the piezoelectric vibrator under the energized state.4.The optimum operat ing frequency under the actual working condition of the traveling wave piezoelectric pump is measured experimentally,and the optimal pumping performance under different operating modes is obtained.The experiment of different working voltage under the optimal working frequency was carried out and obtain the best performanc e when the pumping voltage range from 220 V to 280 V.Combined with the experimental results,the pump performance of each working mode at the best power frequency was compared and the resu lts was get that the fourth-order working status is the best working status and the characteris tics of pumping performanc e under various conditions were also analyzed.The experiment verifies that the dynamic traveling wave type valveless piezoelectric pum p has good driving ability for large viscosity fluid in a certain range and prove it has application prospects.5.Bas ed on the analys is of the working characteristics of the traveling wave piezoelectric pump,two optimization schemes were conceived and des igned,and the working princ iple description and theoretical analys is were carried out,which proved the feas ibility of the scheme and pointed out the direction for the future experimental research.