Abstract: When fluid flows in a spiral tube, the Coriolis force can enhance the mass transfer effect of the fluid and realize the function of conveying fluid. The research shows that the single-screw flow tube without valve pump has the pump function, while the shape of the flow pipe is different from that of the single-screw flow tube, which is better than the one-way pump output, and whether the shape of the flow tube has a pump function or whether its output is lower than the abnormal spiral flow pipe without valve pump, but no relevant research is conducted. In order to better utilize the advantages of the spiral flow tube in the valveless piezoelectric pump, the influence of the arrangement mode of the spiral tube on the output performance of the pump is needed. In this paper, the flow of fluid in the spiral tube is analyzed, and the velocity difference formula between clockwise and anticlockwise flow is derived. It is believed that the flow of the valveless pump in the spiral tube is caused by the flow resistance difference between the inlet and outlet flow tubes. Using the 3D printing technology, a valveless piezoelectric pump with three different flow tube layouts of the same direction spiral, the anomalous spiral and the single spiral flow tube is designed and manufactured, and the flow rate of three kinds of pumps under different frequencies is measured. It is found that the single-screw flow tube has the largest flow of valveless pump at the same voltage, and the best working frequency is also the best; the pump output is also given to the valveless pump of the concentric spiral tube, but the output is small, the driving force is not enough to resist the flow resistance loss along the pipeline, but it can not reflect the advantages of its spiral tube.

Key words: piezoelectric pump, valveless pump, spiral flow tube, Coriolis force, flow tube