Abstract

The current trend in today's technology is the miniaturization of the mechanical components to the extent that they are about to compete with the electronics used to control their performance. In the present study, the transient performance of viscous micropumps will be investigated numerically. The viscous micropump operation depends mainly on viscous forces, and can operate in any situation where viscous forces are dominant. It consists of a cylinder placed eccentrically inside a microchannel with its axis perpendicular to the channel axis. When the cylinder rotates, a net force is transferred to the fluid due to the unequal shear stresses on the upper and lower surfaces of the cylinder, thus causing the fluid to displace. The effect of the microchannel height, rotor eccentricity, Reynolds number, and pump load on the transient performance of the viscous micropump has been studied in detail. The rotor eccentricity was determined to be the parameter that affected the transient performance of the micropump the most significantly. Multi rotor configurations were also examined and proved to enhance the micropump performance. The steady state performance was compared with the available experimental data and was found to be in a very good agreement. This work provides a foundation for future research on the subject of fluid phenomena in viscous micropumps.