集束超音波によって浮遊された液滴の混合時に生じる流動構造

抄録

To clarify the interplay between mixing enhancement and oscillation on the droplets interface, we visualized the flow field in acoustically levitated droplets. Firstly, based on multi-exposure images of internal flow field of droplets, the radial and circumferential flow fields were visualized. Then, the relationship between the flow field inside the droplet, the droplet diameter, and the amplitude of interfacial oscillation was organized. From the result, it is considered that radial flow was generated when the amplitude of the droplet interface relative to the droplet diameter was larger than a certain degree. Secondly, the flow field inside the droplet was measured by PIV. The comparison of the results shows that the larger the amplitude of the interfacial vibration, the faster the radial flow inside the droplet. To further characterize the flow fields in the droplet, the vorticity was quantified. It was found that the vorticities inside the droplet became larger in proportion to the amplitude of the interfacial oscillation.