Research on the performance of a valveless piezoelectric pump with a herringbone bluffbody.

Aiming to improve the output performance of a valveless piezoelectric pump, this article presents a valveless piezoelectric pump with a herringbone bluffbody. The bluffbody is herringbone shaped and distributed in a tapered chamber. The tapered chamber and the bluffbody create a large reverse resistance in the chamber, thus effectively mitigating the backflow problem of the valveless pump. The theoretical analysis determined the relationship between the flow rate and the flow resistance coefficient as well as the variation of the pump chamber volume. It was also concluded that the piezoelectric pump has the best output flow at intrinsic frequencies. Through simulation calculations, the effectiveness of the bluffbody structure in mitigating backflow in piezoelectric pumps is analyzed to provide a reference for experimental prototype design parameters. Finally, a range of prototypes is produced for experimentation. The experimental results show that the designed bluffbody shape can increase the return energy loss to effectively mitigate the return flow issues of the valveless piezoelectric pump, thus improving the output performance. The optimum output flow rate is 158.5 ml/min at 200 V and 52.5 Hz and the tapered chamber angle of 6°, and the bluffbody height, angle, and quantities are 2 mm, 40°, and 2, respectively. The construction of the valveless piezoelectric pump proposed in this research can be used as a reference for subsequent improvements in the performance of valveless piezoelectric pumps, and due to the high output performance, experimental studies can be carried out in applications such as dispensing and heat dissipation in electronic products.