Measurement and Comparison of Flow Fields in the Wake of a Bluff Body using Tomo-PIV, LPTV, and Two-pulse LPTV

Volumetric velocimetry techniques, including tomographic particle image velocimetry (Tomo-PIV), Lagrangian Particle Tracking Velocimetry (LPTV), and two-pulse LPTV, are becoming more common to investigate complex high Reynold's number flows. Despite their popularity, the relative merits, de-merits, and applicability of these methods to investigate specific fluid flow problems is not fully known. In this study, time-averaged and time-resolved velocity measurements of the wake behind a bluff body at Re ~110k is measured using Tomo-PIV, LPTV, and two-pulse LPTV. The effect of processing settings such as Motion Tracking Enhancement (MTE) for tomo-PIV, and particle track length, data assimilation settings for LPTV and two-pulse LPTV on the measured flow fields is investigated. Mean velocity fields and Reynold's shear stresses are compared for time-averaged measurements. For time-resolved measurements, terms in the incompressible vorticity transport equation from the measured flow field is computed and compared.