Research On Design And Performance Of The Valve-less Piezoelectric Micropump With Three-way Diffuser/Nozzle Based On Numerical Simulation

valve-less piezoelectric pump drive fluid by the piezoelectric vibrator which make use of inverse piezoelectric effect. The pump has no moving valve ,so its structure is simple and easy processing and micromation. With these merits ,the pump is fit for use as the drive part of microfluidic system,and has a broad application prospects in aviation and aerospace, medical devices, bio-genetic engineering and other fields.The paper introduced the principles of piezoelectric vibrator and valve-less piezoelectric pump at first. Then theoretical analysis was applied on the flow in the valve-less piezoelectric micropump with diffuser/nozzle, and the property of flow resistance in diffuser/nozzle, the average flow formula and efficiency formula of piezoelectric pump were achieved.However, the valve-less piezoelectric micropump with conventional diffuser/nozzle have a low efficiency, and can't content the condition of large flow with relative small volume. A new type of valve-less piezoelectric micropump with three-way diffuser/nozzle was presented to solve it. The pump was improved design of the valve-less piezoelectric micropump with conventional diffuser/nozzle. Numerical simulation was used to research the flows in the two kinds of tubes, and the result indicated that three-way diffuser/nozzle have higher A than conventional diffuser/nozzle, and can improve the efficiency of valve-less piezoelectric micropump. The same method was used to simulate the flows in the valve-less piezoelectric micropumps with three-way diffuser/nozzle with different structural parameters including radius of corner of bus tube, length of shunt tubes, angle between two shunt tubes, cone angle of shunt tubes and width of shunt tubes, and research the impact of these parameters on the pump. The research finding can provide a way to optimization design of the valve-less piezoelectric micropumps with three-way diffuser/nozzle.Operational process of piezoelectric pump is a complex, multi-field coupling system involving interaction of electric field, stress field, flow field and other physical fields. Considering piezoelectricity and fluid-solid coupling, the soft of ANSYS was used to simulate the operational process of three-way diffuser/nozzle based piezoelectric pump, and research the impact of driving voltage on the piezoelectric vibrator and the effect of vibrator on three-dimensional flow of the pump. The flow-pressure curve could be draw by the simulate data, and the result indicated the three-way diffuser/nozzle based piezoelectric pump have a better performance than the conventional one. Using the same way, the effect of different driving voltages and frequency on the three-way diffuser/nozzle based piezoelectric pump were discovered.