Fluid flow characteristics in xurographic microchannels

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Publication Type thesis
School or College College of Engineering
Department Mechanical Engineering
Author Kolekar, Rahul Dadasaheb
Title Fluid flow characteristics in xurographic microchannels
Date 2009-08-17
Description An experimental study to evaluate fluid flow characteristics in xurographic microchannels was conducted. Microfluidic systems created with xurography are inexpensive compared to those manufactured using other traditional microfabrication technologies. Xurography is a rapid-prototyping technology, making it an ideal tool for microfluidic system development in the laboratory. Flows of water in microchannels with rectangular cross section and channel height on the order of 100 |im in the Reynolds number range from 250 to 3500 were studied. Static pressure measurements were made in the fully developed flow region to obtain the pressure drop at different flow rates. For the microchannel systems with two 90° miter bends, the bend separation distance was more than the re-establishment length following the first bend. Microchannels were characterized using optical microscopy and laser interferometry, which was capable of measuring depths of approximately 100 |um in enclosed microchannels with a relative uncertainty of less than 0.2%. Data for frictional pressure drop in straight sections, critical Reynolds number, and minor losses associated with 90° miter bends were generated. The average Poissuille numbers in fully-developed laminar flow were in excellent agreement with Stokes flow theory for all thirteen microchannels. The critical Reynolds number was in the range of 2250 and 2600 for channels with smooth sidewalls. An early transition to turbulence was evident for the microchannels with flow tripping elements such as adhesive droplets on the sidewalls. The dependence of the laminar Poissuille number on aspect ratio was equivalent to macroscale theory, within the uncertainty of the data. The minor loss coefficients for 90° bends were found to increase with increasing modified aspect ratio. The loss coefficients for every channel were nearly invariant with Reynolds number in the range from 1200 to 2100. A steep increase and a sudden decrease in minor losses was observed for Reynolds numbers less than 1200 and Reynolds numbers greater than the critical Reynolds number, respectively. No microscale effects were evident in the xurographic microchannels.
Type Text
Publisher University of Utah
Subject Microfluidics
Dissertation Institution University of Utah
Dissertation Name MS
Language eng
Relation is Version of Digital reproduction of "Fluid flow characteristics in xurographic microchannels" J. Willard Marriott Library Special Collections TJ7.5 2009 .K65
Rights Management © Rahul Dadasaheb Kolekar
Format Medium application/pdf
Format Extent 96,731 bytes
Identifier us-etd2,129803
Source Original: University of Utah J. Willard Marriott Library Special Collections
Conversion Specifications Original scanned on Epson GT-30000 as 400 dpi to pdf using ABBYY FineReader 9.0 Professional Edition.
ARK ark:/87278/s6126788
Setname ir_etd
Date Created 2012-04-23
Date Modified 2012-05-16
ID 193415
Reference URL https://collections.lib.utah.edu/ark:/87278/s6126788