  Solvent exchange is a process involving mixing between a good solvent with
dissolved solute and a poor solvent. The process creates local oversaturation
which causes the nucleation of minute solute droplets. Such ternary systems on
a macro-scale have remained unexplored in the turbulent regime. We
experimentally study the solvent exchange process by injecting mixtures of
ethanol and trans-anethole into water, forming a turbulent buoyant jet in
upward direction. Locally, turbulent mixing causes oversaturation of the
trans-anethole following turbulent entrainment. We optically measure the
concentration of the nucleated droplets using a light attenuation technique and
find that the radial concentration profile is sub-Gaussian. In contrast to the
entrainment-based models, the spatial evolution of the oversaturation reveals
continuous droplet nucleation downstream and radially across the jet, which we
attribute to the limited mixing capacity of the jet. Though we are far from a
full quantitative understanding, this work extends the knowledge on solvent
exchange into the turbulent regime, and brings in a novel type of flow,
broadening the scope of multicomponent, multiphase turbulent jets with phase
transition.
