Optimal theoretical design of 2-D microscale viscous pumps for maximum mass flow rate and minimum power consumption

The present paper addresses the effect of geometric parameters such as channel height and rotor eccentricity on the mass flow rate and power consumption of a two-dimensional microscale viscous pumps. The objective is to maximize the mass flow rate and at the same time minimize shaft power consumption when an external pressure load is applied along the channel that houses the rotor. Three different viscous micropump configurations were considered, a straight housed pump (I-shaped housing) and two curved housed pumps (L- and U-shaped housings). Because the performance of a microviscous pumps are based on the asymmetric placement of the rotor within the surrounding housing, the numerical results show that the rotor eccentricity and the channel height have a major effect on the mass flow rate generated by the rotor and on the shaft power demanded by the rotor. Preliminary simulations showed that mass flow rate is maximized when the eccentricity is small. The results also show that micropumps with curved housing (i.e., L- and U-shaped configurations) not only provide higher mass flow rates when compared with straight housed pumps, but also demand less shaft power to operate. Optimized geometric dimensions of all three configurations are presented for several values of the Reynolds number and pressure load.