Surface Tension Measurement at High Temperatures by using Dynamics of Melt Flow

Abstract

Surface tension of melts at high temperature has significant effects on different industrial processes. In a new containerless method for surface tension measurement, an atmospheric radio-frequency inductively coupled plasma melts metallic or ceramic rods and a high-speed charge-coupled device records the drop formation caused by melting. Pendant drops produced by the melt flow are compared with the theoretical Young–Laplace (YL) profiles. Moreover, the dynamics of the melt flow is mimicked by using numerical simulations of drop injection from a nozzle. The numerical model solves the axisymmetric Navier–Stokes equations for both the melt and the surrounding gas by using the finite volume method. Since the YL equations provide theoretical pendant drop profiles based on an inviscid quasiequilibrium condition, a detailed study of the differences between experimental, numerical, and theoretical profiles demonstrates some of the hydrodynamic effects influencing the surface tension measurement methods, which are based on drop profiles. Results from this surface tension measurement method, in addition to a discussion on the hydrodynamic effects, are presented.