Validating ground-based aerodynamic levitation surface tension measurements through a study on Al₂O₃

Area of Science:

• Materials Science
• Fluid Dynamics
• Thermodynamics

Background:

• Surface tension of molten materials is crucial for various industrial processes.
• Levitation techniques are used to measure surface tension, but gravity affects resonant frequencies.
• Aerodynamic levitation (ADL) lacks a mathematical correction for gravity-induced frequency shifts, impacting measurement validity.

Purpose of the Study:

• To compare surface tension measurements of molten Al2O3 using different methods.
• To validate the accuracy of ground-based aerodynamic levitation (ADL) for surface tension measurements.
• To assess the deviation of ADL measurements from microgravity conditions.

Main Methods:

• Comparison of surface tension data from front tracking (FT) simulations.
• Utilized the drop-bounce method with ADL, simulating microgravity via free-fall.
• Employed the oscillating drop method with ADL, analyzing resonant frequencies.

Main Results:

• The oscillating drop method with ground-based ADL showed only a small deviation in surface tension measurements compared to microgravity.
• The l=2 m=0 mode resonant frequency was used for calculations in the oscillating drop method.
• FT simulations provided a benchmark for comparison.

Conclusions:

• Ground-based ADL using the oscillating drop method is a valid technique for measuring molten material surface tension.
• The identified deviation is minimal, suggesting reliable measurements can be obtained without true microgravity.
• This finding enhances confidence in using ADL for surface tension analysis.