Viscosity & Surface Tension Measurement Using Resonance Of Levitated Molten Droplets*

This research investigates a novel method using Faraday instability on a spherical drop to measure viscosity and surface tension in liquid metals. These properties play a crucial role in modeling welding, in-situ space crystal growth, and additive manufacturing processes like Direct Energy Deposition (DED). By subjecting the drop to a periodic electric field matching its natural frequency, resonance is induced, leading to the formation of unique modal structures on the drop's surface. The study explores different analytical approaches to analyze these resonant features and highlights their advantages. Furthermore, experimental data for Zirconium and Tin are presented, demonstrating the applicability of the method to different liquid metals. 

 

Acknowledgements 

The authors acknowledge funding from NSF via grant number CBET-2025117 and NASA via grant number NNX17AL27G