SINOPSIS

The wake of a streamwise oscillating cylinder is presently investigated. The Reynolds number, based the cylinder diameter d, investigated is 300. The cylinder oscillates at an amplitude of 0.5d and a frequency f_e/f_s, where f_e is the cylinder oscillating frequency and f_s is the natural vortex shedding frequency of a stationary cylinder. Under these conditions the flow is essentially two dimensional. A two-dimensional direct numerical simulation (DNS) scheme has been developed to calculate the flow. The DNS results display a street of vortices symmetrical about the centreline, each containing two counter-rotating structures, which is in excellent agreement with measurements. The drag and lift on the cylinder have also been examined.