%0 Journal Article
%T On Laminar Flow in Microfabricated Channels with Partial Semi-Circular Profiles
%A William J. Federspiel
%A Isabella Valenti
%J Open Journal of Applied Sciences
%P 28-34
%@ 2165-3925
%D 2012
%I Scientific Research Publishing
%R 10.4236/ojapps.2012.21003
%X Soft and hard micromachining techniques used to develop microfluidic devices can yield microchannels of many different cross-sectional profiles. For semi-circular microchannels, these techniques often produce only <i>partial</i>semicircular (PSC) cross-sections. This study investigated fully developed laminar flow in PSC microchannels as a function of a circularity index, ¦Ê, defined as the ratio of the radiuses along the curved and flat surfaces of the PSC profile. A correction factor, K, to the Hagen-Poiseuille relation was determined and was well-fitted by the power-law relationship K=5.299/¦Ê<sup>2.56</sup>. Actual correction factors were compared to estimates based on several hydraulic models for flow in microchannels of arbitrary cross-section, as well as the half-ellipsoid cross-section. The level of wall shear stress, when normalized by the pressure drop per unit length, increased approximately linearly with increase in the circularity index, ¦Ê.
%K Hagen-Poiseuille Flow
%K Poiseuille Flow
%K Flow Resistance
%K Wall Shear Stress
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=18290