  We present a unique pipe flow rig capable where simultaneous particle
tracking and flow velocity measurements in a dilute, neutrally buoyant
particulate pipe flow in regimes of transition to turbulence. The flow consists
of solid glass spheres for the disperse phase, and a density-matching fluid for
the carrier phase. The measurements are conducted using a bespoke, combined 2D
PIV/ PTV technique. The technique takes advantage of a phase discrimination
approach that involves separating the disperse and carrier phases based on
their respective image characteristics. Our results show that the rig and the
technique it implements can be employed to study transitional particulate pipe
flows at dilute concentration.
