Measurement of surface tension with free-falling oscillating molten metal droplets: a numerical and experimental investigation

Abstract Rayleigh’s equation has been widely used to determine surface tension from oscillating droplets. In this study, the use of a drop-on-demand droplet generator is proposed create free-falling, oscillating, molten metal droplets for purpose. To examine applicability generator, extensive numerical simulations in three and two-dimensions were performed. The effect gravity, initial velocity deformation on frequency pattern oscillation was investigated. enables creation thousands course single experiment have much shorter exposure time possible unwanted contaminations, due rapid measurement principle. Furthermore, adjustable nozzle size provides flexibility terms size, which affects range validity method. validate method, copper an argon atmosphere determined over temperature 1400–1620 K. linear relation expressed as σ [mN m −1 ] = (1307 ± 98) − (0.22 0.015) ( T −1356) K).