Abstract
Vortex structures in a circular synthetic jet were investigated numerically by using Large Eddy Simulation. The instantaneous velocity vector and vorticity were calculated for two non-dimensional strokes of L/d = 1.18 and 4.72. The simulation results indicate that a vortex ring is formed in a cycle and travels to downstream. The vortex rings travel to downstream and collapse in further downstream. In case of a long stroke L/d = 4.72, it was observed the vortex ring accompanies a small trailing vortex ring. The characteristics of these vortex rings were examined by the iso-surfaces of the vorticity magnitude and the circulation of the vortex rings.
