Vortex wave flow field within a channel was measured using particle image velocimetry (2DPIV). Instantaneous velocity vector field measured was reconstructed with dominant modes using POD technology. Average velocity and turbulent kinetic energy distribution were obtained using POD reconstructed field. Turbulent kinetic energy dissipation rate was estimated by using a large eddy PIV method. It shows that dominated structure of original flow field were characterized by reconstruction of flow field. Noise and other interference information were eliminated. Large eddy PIV method estimates effectively distribution of kinetic energy dissipation rate. Turbulent kinetic energy is small in vicinity of wall. Turbulent kinetic energy increases near center of channel region, which is characteristics of jet. Kinetic energy dissipation rate peak appears in vicinity of central region and channel wall. Away from wall kinetic energy dissipation rate is increases initially, and decreased gradually until it reaches a peak.

To study influence of run-time on dynamic characteristics of water/oil separation, a mathematical model is established to describe flow field in vacuum oil purifier. Evaporation of droplet phase transition equations are established, considering effect of three-phase flow of oil/water/vapor and water droplets evaporation phase change. Influences of run-time on oil/water/vapor three-phase volume fraction distribution and axial dehydration rate are analyzed. Dynamic characteristics of oil/water/vapor three-phase flow at different run-time is indicated. Efficiency of dehydration of water/oil separation is enhanced with run-time. It provides a foundation for further research on water/oil separation mechanism in vacuum oil purifier.