Investigation of effect of different cross-sections of rotor on two-dimensional transient flow in viscous micropumps

In this paper, the effect of rotor cross-section geometry in viscous micropumps is studied for optimizing the flow and maximizing the exit flow rate using the Overset Grid method. The main construction of viscous micropumps consists of a rectangular channel and a rotor with circular cross-section which rotates eccentrically and perpendicular to the channel axis. In this paper, the effects of channel height, rotor eccentricity and channel pressure difference on the average velocity at the outlet of microchannel in the presence of circular, square, rectangular and elliptic rotor cross-sections are investigated. The flow equations are solved two-dimensionally, using incompressible finite volume method. The obtained results show that the maximum value of the exit average velocity is obtained at a microchannel of 1.5 times of the rotor diameter. However, increasing the rotor eccentricity and the angular velocity of the rotor causes the exit velocity magnitude in the micropump to increase. The obtained results show very good agreement with existing experimental and numerical results.