Modeling of pressure and shear-driven flows in open rectangular microchannels (Q1434598)

The mean velocity of a liquid flowing in a rectangular microchannel is studied both numerically and analytically for contact angles ranging from \(0^\circ\) to \(90^\circ\) and for the full spectrum of channel aspect ratios. The primary contribution of this paper is the derivation of analytical expressions that are very comprehensive in their range of application, yet remain relatively simple to apply and accurate within a few percent for most flow regimes of interest. These analytical approximations are constructed by matching of asymptotic solutions that apply in limiting regimes where the fluid depth at the channel centerline is either very small or very large compared to the channel width.