Flow visualisation of a rotating sphere

Dye flow visualisation of a rotating sphere at different rotation speed ratios. The rotation speed ratio is defined as alpha = omega * D/(2U). The experiments were conducted in the FLAIR Water Channel Laboratory at Monash University, Australia.

Publication: Sareen et al (2018), Journal of Fluid Mechanics 837: 258-292;
doi:10.1017/jfm.2017.847.