Transition from symmetric to asymmetric scaling function before drop pinch-off

Area of Science:

• Fluid dynamics
• Rheology
• Surface science

Background:

• Understanding fluid drop formation and pinch-off is crucial in various industrial processes.
• The dynamics of viscous fluid jets breaking up are complex and depend on fluid properties and surrounding environment.

Purpose of the Study:

• To experimentally investigate the pinch-off dynamics of a glycerin-water mixture at a nozzle.
• To analyze the scaling behavior of the fluid neck during the pinch-off process.

Main Methods:

• Experimental study of drop pinch-off using a glycerin-water mixture.
• Observation and measurement of the fluid neck diameter and velocity during shrinkage.
• Application of scaling functions to describe the neck's geometry.

Main Results:

• The fluid neck diameter shrinks at a constant velocity initially.
• A distinct transition point was observed where the shrinkage velocity decreases.
• The neck shape follows a symmetric scaling function before the transition and an asymmetric one afterward.

Conclusions:

• The pinch-off process exhibits distinct stages with changes in shrinkage dynamics.
• Symmetric and asymmetric scaling functions accurately describe the fluid neck's geometry at different stages.
• Experimental results provide insights into the physics of viscous drop formation.