Flow characterization study of straight minichannel devices using microPIV

Abstract

The visualization of the internal flow field in a mini-channel rig and their validation by CFD numerical comparison

In the last decades there has been a growing interest to develop mi-croscale devices that can manipulate and transport relatively small volumes of fluids. These devices have applications in many areas of engineering, including nanotechnology devices, propulsion and power generation of micro-satellites, inkjet printer heads and bioanalytical instruments. Flow behaviour in these small domains can be often counterintuitive because of the low Reynolds number or the relative importance of surface forces. The surge of microfluidic devices has created a need of diagnostic tools with spatial resolution on the order of several microns and lower. The current study has been motivated by the need to provide more information about flows in micro and mini scales. It is specially re-markable the lack of studies related to flows inside channels of cross sections in the order of 1mm2 and high roughness. The majority of the studies use devices with smooth surfaces with a roughness below 1µm. By visualizing and analysing the flow in a 1mm2 squared sec-tion channel of a roughness on the order of 10 µm this study brings the opportunity to present useful information not currently available, information that, moreover, is closer to industrial applications. This document has two main parts. Regarding those interested in microPIV it is first explained the main aspects of microPIV method-ology with the aim to provide a simple but effective guide and to avoid spending so much time compiling the information spread throughout documents. The second main part contains the experimental study itself, divided with several sections which sequentially discuss all as-pects related to the experimental setup, data preprocessing, analysis, postprocessing and validation by analytical equations. Finally, some improvements and further studies are proposed.