Single-phase liquid friction factors in microchannels

The validity of friction factor theory based upon conventional sized passages for microchannel flows is still an active area of research. Several researchers have reported significant deviation from predicted values, while others have reported general agreement. The discrepancies in literature need to be addressed in order to generate a set of design equations to predict the pressure drop occurring in microchannel flow devices. The available literature on single-phase liquid friction factors in microchannels is reviewed. A database is generated to critically evaluate the experimental data available in the literature. An in-depth comparison of previous experimental data is performed to identify the discrepancies in reported literature. It is concluded that the conventional Stokes and Poiseuille flow theories apply for single-phase liquid flow in microchannel flows. New experimental data is presented and the pressure drop components are carefully analyzed. The developed procedure properly identifies the components of total pressure drop that allow for improved agreement with conventional theory. (C) 2006 Elsevier SAS. All rights reserved.