We propose viscosity measurements of molten oxides using Aerodynamic Levitation (ADL) with CO2-laser heating which can achieve container-less and non-contact conditions for measurements. For viscosity measurements, we used a unique vibration method that causes oscillations in a sample and levitates a gas via acoustic speakers. Using these techniques, we clarified the surface oscillation excitation mechanism and then, based on this understanding, we measured the viscosity of molten Al2O3 and its temperature dependence.
In this study, we measured the density of a molten oxide of SiO2-CaO-Al2O3 system using Aerodynamic Levitation (ADL) with CO2-laser heating which can achieve container-less and non-contact conditions for measurements. For density measurements, we improved our ADL system to obtain the appropriate shape for the droplet based on the previously reported system by Langstaff et al. We measured the density of molten CaAl2O4 between 1600 to 2300K. We conclude that our ADL system has the potential to precisely measure molten oxide density due to good agreement of our density of CaAl2O4 with previous data. Using these techniques, we succeeded also to measure the density of a molten SiO2-CaAl2O4 oxide system and discussed the molar volume change by varying the SiO2 composition.
We focus on dynamic behavior of the macroscopic contact line (MCL) of a droplet spreading on a substrate after an interaction with a spherical particle settled on the substrate. We will show that there exist three different regimes of the MCL behavior for different ranges of the capillary number. In the case of a small capillary number, the MCL exhibits a sharp acceleration after the interaction with the particle that remains at its original position In the case of a large capillary number, on the other hand, the MCL advances without any significant variation of behavior produced by the interaction with the particle. The particle is sucked toward the bulk of the droplet after the interaction. In the case of a moderate capillary number, the MCL exhibits gradual acceleration after the interaction with the particle, accompanied by a slight movement of the particle toward the droplet. We will also discuss the effect of the particle size on the behaviors of the MCL.