Velocity fluctuations in the shear layer of monoethylene glycol positively buoyant jets in quiescent water

Positively buoyant jets play a key role in various environmental and industrial processes, including the discharge of industrial effluents, pollutant dispersion in the atmosphere, and mixing operations. In this study, we experimentally investigate the dynamics of positively buoyant jets generated by the injection of monoethylene glycol (MEG) solutions into quiescent water. The experiments are performed in a still water tank, where a MEG jet is injected vertically downward. Velocity and turbulence fields are characterized using Particle Image Velocimetry (PIV), while concentration distributions are measured using a fluorescence-based technique. This dual approach allowed for a detailed evaluation of the interplay between buoyancy and momentum in governing jet entrainment and mixing. Results show a strong dependence of the overall jet behavior on both the injection velocity and MEG concentration. This study provides new insights into the influence of buoyancy and viscosity on the dispersion of miscible jets and offers a foundation for future modeling of these complex flows.