3-D Particle Tracking Velocimetry (PTV) in gas flows using coloured tracer particles

Abstract

Although relatively often used for liquid flows, Particle Tracking Velocimetry (PTV) is still considered as a major challenge in gaseous flows. One of the main objections is the higher tracer density necessary for gaseous measurements [1, 2], resulting from higher characteristic speeds and smaller spaceand time-scales of the important flow structures. Nevertheless, the widely recognized interest of Lagrange-based measurements (such as PTV) for the investigation of turbulence and vortical structures in real flows [3] is a sufficient reason to face all these challenges. The solution proposed in this work is to employ coloured particles and use the associated separation into different colour classes. Considering separately each resulting colour class, the apparent particle density is decreased without restrictions in the measurement accuracy.