Microscale loss coefficients through expansion and contraction xurographic microchannels
Xurography is a novel manufacturing process for microfluidic systems, providing rapid prototyping capability at low cost compared to traditional microfabrication technologies. An experimental study of flow characteristics in rectangular xurographic microchannels is reported. Mean microchannel depth, defined by the thickness of the double-sided adhesive kapton tape that forms the channel pattern, is ~110 ?m. The microchannels are capped with glass and mechanically reinforced to withstand the high operating pressures that accompany high Reynolds number Re flow (250 – 3500). Channel aspect ratios range from 0.45 to 0.074. Width and length measurements are performed using optical microscopy. Microchannel height is measured using a unique nondestructive laser interferometry technique, capable of accurate measurement of the enclosed, compressed microchannels. Data are reported for friction factor, critical Reynolds number, and minor losses in expansions and contractions. Expansion and contraction area ratios are 2, 3, and 5. The experimental Poissuille number in laminar flow for all aspect ratios is in good agreement with theoretical values.
University of Utah;
Contraction; Expansion; Microchannel; Microscale; Minor loss; Xurography