Effect of Particle Image Velocimetry Setting Parameters on Local Velocity Measurements in an Agitated Vessel

• Published in: Chemical engineering & technology Vol. 42; no. 4; pp. 827 - 834
• Main Authors: Šulc, Radek, Ditl, Pavel, Jašíkova, Darina, Kotek, Michal, Kopecký, Václav, Kysela, Bohuš
• Format: Journal Article
• Language: English
• Published: Frankfurt Wiley Subscription Services, Inc 01.04.2019
• Subjects: Fluctuation velocity; Fluid dynamics; Impellers; Mixing; Parameters; Particle image velocimetry; Recording; Rushton turbine; Rushton turbines; Sampling; Spatial resolution; Turbulence; Velocity gradient; Velocity measurement
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.201800589

Although they are obtained under the same conditions, results on the flow field in an agitated vessel achieved using particle image velocimetry (PIV) may vary due to differences in the PIV conditions. The influence on turbulence characteristics of the main PIV setting parameters, i.e., PIV spatial resolution, sampling frequency, and recording time, was investigated. Tests were performed with three different liquids in a developed turbulent field for a Rushton turbine impeller using two‐dimensional time‐resolved PIV. To obtain the relevant velocity gradients, a minimum recording time is needed. No effect of sampling frequency was observed if the sampling frequency was higher than approximately 17 times the impeller frequency, which is about three times the impeller blade frequency. The impact on turbulence characteristics of the main particle image velocimetry setting parameters was investigated for a Rushton turbine impeller. To obtain the relevant data for velocities and fluctuation gradients, a minimum recording time is needed. No effect of sampling frequency was observed if the sampling frequency was higher than approx. 17 times the impeller frequency.