Volumetric-correlation PIV to measure particle concentration and velocity of microflows

• Published in: Experiments in fluids Vol. 52; no. 3; pp. 663 - 677
• Main Authors: Nguyen, Chuong Vinh, Carberry, Josie, Fouras, Andreas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2012; Springer
• Subjects: Applied fluid mechanics; Autocorrelation; Biological; Density; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Exact sciences and technology; Fluid dynamics; Fluid- and Aerodynamics; Fluidics; Fundamental areas of phenomenology (including applications); Heat and Mass Transfer; Instrumentation for fluid dynamics; Mathematical analysis; Particle image velocimetry; Physics; Research Article; Temporal resolution; Three dimensional; Velocity measurement; Channel Depth; Particle Image Velocimetry Technique; Interrogation Window; Particle Tracking Velocimetry; Particle Image Velocimetry; Concentration measurement; Three dimensional flow; Particle image velocimetry; Experimental study; Velocity measurement; Microstructure; Microfluidics
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-011-1087-1

Volumetric-correlation particle image velocimetry (VPIV) is a new technique that provides a 3-dimensional 2-component velocity field from a single image plane. This single camera technique is simpler and cheaper to implement than multi-camera systems and has the capacity to measure time-varying flows. Additionally, this technique has significant advantages over other 3D PIV velocity measurement techniques, most notably in the capacity to measure highly seeded flows. Highly seeded flows, often unavoidable in industrial and biological flows, offer considerable advantages due to higher information density and better overall signal-to-noise ratio allowing for optimal spatial and temporal resolution. Here, we further develop VPIV adding the capability to measure concentration and increasing the robustness and accuracy of the technique. Particle concentrations are calculated using volumetric auto-correlations, and subsequently the velocities are calculated using volumetric cross-correlation corrected for variations in particle concentration. Along with the ability to calculate the particle concentration profile, our enhanced VPIV produces significant improvement in the accuracy of velocity measurements. Furthermore, this technique has been demonstrated to be insensitive to out-of-plane flows. The velocity measurement accuracy of the enhanced VPIV exceeds that of standard micro-PIV measurements, especially in near-wall regions. The 3D velocity and particle-concentration measurement capability of VPIV are demonstrated using both synthetic and experimental results.