High-speed imaging study for characterizing the effect of physical properties on breakup dynamic behavior of oil drop in turbulent field

Liquid–liquid dispersion has wide practical applications, increasing the significance of characterizing the drop breakage to understanding the drops dynamic behavior in turbulent flow systems. In the present work, the drop breakup behavior of oils having different physical properties was investigated in a stirred tank equipped with a Rushton turbine impeller using high-speed imaging method. Four oils were investigated, including crude oils and lubrication oils, for a range of Reynolds numbers (Re). The dynamic behavior of each drop was quantitatively analyzed to obtain a deeper insight into the effect of viscosity and surface tension on the breakup mechanism by determining the drops number and size distributions. The degree of drop deformation and breakup probability were also quantified and discussed. The two types of crude oils exhibited high breakage intensity (high breakup probability, high number of daughter drops, and smaller size of daughter drops) owing to their low viscosity and surface tension. Lubrication oils showed lower breakage probability, produced larger daughter sizes, and exhibited higher elongation deformation owing to their higher viscosity and surface tension compared to crude oils. Highly deformed shapes close to the impeller blades were observed for the crude oils, especially at high Re that resulted in highest number of daughter drops when breaking up. About 90% of breakages occurred in the impeller region within a distance of 1/2 blade length from blade edges.