Effects of particle size, concentration and surface coating on turbulent flow properties obtained using PIV/PTV

It is commonly assumed that seeding particle parameters have negligible influence on the deduced velocity field when making measurements using Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) methods. Although there is extensive research examining various aspects of PIV/PTV analysis there is limited research examining the effects of the seeding particles on the turbulent flow results. In this study, we investigated the influence of the particles on the derived fields. For that purpose, we have measured the velocity field in a canonical flow of lid driven cavity using Ply and PTV while varying only the particle parameters. We examine the particle influence on the turbulent quantities as well as the velocity derivatives by applying a standard statistical test. At higher Reynolds numbers the influence of the particle parameters was larger. The size of seeding particles had the largest influence on velocity and acceleration in comparison to the other parameters. The concentration and the chemical treatment did not affect the results independently. However, there is some effect when these two parameters were changed in conjunction. (C) 2012 Elsevier Inc. All rights reserved.