Bluff-body propulsion produced by combined rotary and translational oscillation

Flows produced by combined oscillatory translation and rotation of a circular cylinder in quiescent fluid have been studied using a two-dimensional direct numerical simulation technique. Results are presented for one set of the five dimensionless groups which characterize these flows, for which it is found that a streaming flow normal to the axis of translation is generated. The consequent reaction force is then used to propel the cylinder in the direction opposite to the jet, thus demonstrating a novel propulsion mechanism for bluff bodies.