Geometrical analysis of diffuser-nozzle elements for valveless micropumps

This paper reports a geometrical analysis and tuning-approach for diffuser-nozzle elements for valveless micropumps. Finite element analysis studies are performed in order to investigate the impact of the angle, curvature ratio, and length of the diffuser on the pumping efficiency. Parametric sweep studies are implemented at Reynolds number (Re) values ranging from 10 to 100 while observing the pressure coefficients in the nozzle and diffuser directions, as well as the flow separation and the resultant efficiency of the diffuser. The results suggest that a diffuser with an angle of 10° and a curvature ratio of 0.4 possesses the highest efficiency among the other diffusers within the Re range of this study. In addition, it is observed that the length of the diffuser has a positive effect on the efficiency, where the length is usually restricted by the overall size of the device. The results provide comprehensive designing guidelines for diffusers elements that can be used in microfluidic devices for various biomedical applications