Vortex shedding in the wake of a rotating circular cylinder at low Reynolds numbers

Measurements are presented which show that, at a Reynolds number of 60, the Strouhal number for the shedding of vortices from a rotating cylinder is only weakly dependent on the value of alpha, the ratio of the cylinder's peripheral speed to its translational speed, up to the alpha value at which shedding is suppressed. This finding agrees with the theoretical results of Kang et al (1999 Phys. Fluids 11 3312), and strongly disagrees with those of Hu et al (1990 Phys. Fluids 8 1972). In addition, measurements were made to determine the alpha value at which shedding is suppressed for Reynolds numbers between 50 and 65. The results indicate a flow more stable than that predicted by both Hu et al and Kang et al.