PIV measurement of internal flow in a levitated droplet

Under the microgravity environment, production of new and high quality material is expected. Large droplet is preferable for such a containerless processing under the microgravity environment. However, effect of surface instability and internal flow become remarkable when the droplet becomes large. Elucidation of internal flow and surface instability on a levitated droplet is required for the quality improvement of new material under the microgravity environment. The objective of the present study is to clarify the critical condition of the occurrence of internal flow and surface instability.At the first, multidimensional visual measurement is conducted to investigate the internal flow structure in a levitated droplet. It was suggested that complex flow with the vortex in the levitated droplet is generated.Finally, the stereo imagery for performing 3-D PIV is acquired. The possibility of 3-D PIV to levitated droplet was examined.