A CFD study of the dynamic response of a rotating cylinder in a current

A new form of dynamic response for a flexibly mounted, rotating cylinder in a current, as observed in experiments, has been investigated through 2-D, laminar CFD. Orbital response of opposite rotation to that of the cylinder and with amplitudes of several diameters can occur with a maximum at alpha = 0.3, where alpha is the ratio of current velocity to rotation speed of the cylinder surface. Instantaneous flows and forces for this alpha value are related to those for a nonresponding cylinder but it is shown that the forcing is far from quasi-steady and is due to rapidly changing wake structures during part of a cycle. (C) 2001 Academic Press