Numerical Simulation And Experimental Study Of Valveless Piezoelectric Hybrid Pump With Built-in Obstructions

With the rapid development of micro-machining technology in recent years,the research on piezoelectric pump and micro-mixer at home and abroad is also in-depth,and its application range is more and more extensive.As one of the active micro hybrid driving methods,piezoelectric pump drive generates vibration through the applied sinusoidal driving signal.Compared with other hybrid methods,it has the advantages of good response and accurate output control.However,there are few studies on the combination of the two,only a simple series combination,such a hybrid structure is more complex and not close on the whole.Therefore,how to better combine the piezoelectric pump and micro mixer has become a direction of the development of piezoelectric pump.This paper presents a valveless piezoelectric hybrid pump with built-in resistance fluid in the channel and cavity.Due to the asymmetry of the built-in two kinds of obstructions,there is a flow difference,and it can change the fluid direction to enhance the transverse mass transfer.Through the setting of the pump cavity and flow channel structure,the purpose of both pumping and mixing of valveless piezoelectric pump is realized.This paper adopts the method of combining the numerical simulation analysis of fluent module in ANSYS Workbench software with the performance experiment of hybrid pump.The specific research contents are as follows:Firstly,the working mechanism of the proposed valveless piezoelectric hybrid pump with built-in obstructions in the channel and cavity is analyzed,and it is proved that it has reliable pumping and mixing effect.Fluent is used to simulate the hybrid pump.The simulation results show that the new hybrid pump has good mixing and pumping functions.Among them,the triangular obstructions shaped resistance fluid in the channel has a greater impact on the pumped liquid volume of the hybrid pump in unit time.With the increase of the number of triangular obstructions shaped resistance fluid,the pumped liquid volume in unit time gradually increases;With the increase of the distance between the obstruction and the side wall of the channel,the amount of pumped liquid per unit time decreases gradually.The semi cylindrical obstructions in the pump cavity has a greater impact on the mixing capacity of the hybrid pump,and the semi cylindrical obstruction has a greater impact on the mixing capacity;With the increase of the number of semi cylindrical obstructions,the mixing ability increases gradually.According to the simulation,the prototype of the hybrid pump is made,the performance test platform is built,and the performance experiment of the hybrid pump is carried out.The experimental results show that under the driving of sinusoidal signal with voltage of 70 V and frequency of 10 Hz,the liquid volume pumped by the hybrid pump per unit time reaches 5.26ml/min;Matlab software is used to process the mixed image,and the quantitative analysis shows that the mixing effect is good.The influence of the two kinds of obstructions and their structural changes on the performance of the hybrid pump is consistent with the simulation results.In addition,the influence of driving voltage amplitude and frequency on the hybrid pump is also tested.The experimental results show that with the increase of driving voltage and frequency,the pumped liquid volume per unit time first increases and then decreases.The peak appears when the frequency is 10 Hz,the pumped liquid volume per unit time at the peak is 5.26ml/min,and its working frequency range is 7-12Hz;Its mixing ability increases with the increase of driving voltage and frequency.With the increase of the driving voltage amplitude,the pumped liquid volume per unit time of the hybrid pump also increases.When driven by the sinusoidal signal of 83.3V and 10 Hz,the pumped liquid volume per unit time can reach 12.26ml/min;With the increase of the driving voltage amplitude,the mixing ability basically does not change.Therefore,the hybrid pump proposed in this paper has good pumping and mixing capacity,and can be better applied to micro mixing fields such as medical treatment and chemical industry.