Asymmetrical wake generated by a spinning cylinder

An extended set of measurements has been carried out on a developing turbulent wake behind a spinning circular cylinder immersed in a uniform stream. Various moments of the velocity signals have revealed the effect of the rotation upon characteristic parameters of the flowfield. For small values of rotation, where the circumferential velocity is less than the freestream velocity, a quasiconventional turbulent wake behavior obtains. At high values of rotation, the magnitudes of all dynamic turbulent fluctuations decrease substantially due to the suppression of the Kantian vortex street. As well, it was observed that a region of negative production was generated in the developed flow for those cases where the circumferential velocities were comparable to the freestream velocity. This aspect is explored in considerable detail.