Jet breakup regimes in liquid-liquid Taylor vortex flow

Optical experiments were used to identify breakup regimes for a liquid jet injected into in a second immiscible liquid undergoing turbulent Taylor vortex flow. Four jetting breakup behaviors were observed and these were compared with analogous jetting regimes in quiescent liquid-liquid systems as well as liquid-gas systems with a gaseous crossflow. Several jet breakage regime maps for liquid-liquid Taylor vortex flow were generated using jet Reynolds number, Ohnesorge number, crossflow Weber number, and momentum flux ratio as organizing parameters. However, selection of the breakup mechanism was found to depend primarily on the jet Reynolds number and was largely independent of parameters characterizing the fluid crossflow, such as the azimuthal Reynolds number and crossflow Weber number. This finding is consistent with previous observations that the downstream droplet size distribution in Taylor vortex flow is relatively insensitive to parameters other than the jet Reynolds number. Lastly, the transitions between the four identified jet breakage regimes were found to be coincident with changes in the mean droplet size observed downstream from the inlet jet. (C) 2020 Elsevier Ltd. All rights reserved.