Performance Improvement and Two-Phase Flow Study of a Piezoelectric Micropump with Tesla Nozzle-Diffuser Microvalves

The Present article aims to design a piezoelectric micropump using a combinational form of microvalves with sufficient diodicity in low-pressure gradients. The goal is to enhance the capability of piezoelectric micropumps with Tesla-type valves in order to deliver insulin. Tesla-type valves are in the category of passive valves which have sufficient diodicity in case of high-pressure gradients. However, low mass flow rates are often required in drug delivery devices. In this paper, the performance of MT135 Tesla-type valve in low pressure-gradient flows has been investigated and a range of reunio‎n angles, which have not been studied before has been examined by numerical solutions. Inspired by nozzle-diffuser valve types, some changes in the bypass path of the microvalve have been exerted to boost the diodicity of the valve in low-pressure conditions that resulted in 9.97% increase of diodicity. At last but not least, the velocity gradients in singlephase flow of water has been attained and performance of micropump toward other kinds of flows has been investigated by a volume of fluid (VOF) model including water as the primary phase and air as the secondary one. To complete the analysis, a VOF model consisting of an arbitrary kind of Casson fluid with the primary phase of water was reached and discussed.