Avaliação de confiabilidade na medição de velocidade utilizando a técnica de velocimetria por imagem de partículas aplicada a microcanais

Abstract

The Micro-Resolution Particle Image Velocimetry (μPIV) is a method used for the flow characterization in microfluidic systems due to its non-intrusive nature, spatial resolution and velocity field measurement capability; interesting for microscale flow analysis. However, in order to evaluate the quality of quantitative velocity measurements obtained through this technique, estimation for the measurements uncertainty sources and the interactions of several experimental and typical parameters of its application is a challenging task. Therefore, this study aims to analyze the reliability in velocity field measurements using the μPIV technique through uncertainty sources quantification in flows inside straight microchannels using different fluids (deionized water, glycerol solution 78% and light mineral oil) and volumetric flow rates between 0.02 and 199 μL/min. The influence of processing, optical, dynamic and experimental parameters on the measurements of velocities was evaluated comparing it with the analytical solution for Newtonian fluid laminar flow, obtaining an agreement of more than 95% between experimental and theoretical data in the region of maximum speed. In addition, after evaluating the influence of the aforementioned parameters, it was verified the efficiency of measurements of velocity field of the flow in a microchannel in zigzag considering the experimental uncertainties, observing the capability of adaptive correlation techniques on experimental velocity fields measurement.