Phaseresolved instantaneous flow fields were experimentally measured by using particle image velocimetry (PIV) for the synthetic jets

which were excited by a specific sparkdischarge actuator. The unsteady flow structures of the sparkexcited synthetic jet during the developing process were captured. Meanwhile

the instantaneous velocities of the sparkexcited synthetic jet at some fixed axial positions downstream the nozzle were measured by using the hotwire anemometer. The effects of the spark-excitation parameters (such as discharge frequency and capacitance energy storage) on the synthetic jet were preliminarily analyzed. It was revealed that the sparkexcited synthetic jet took on sphericalshape diffusion near the jet nozzle at the initial stage of synthetic jet formation. As the synthetic jet developed

a series of vortices were induced by the shear and entrainment actions of the synthetic jet. The maximum peak normalvelocity appeared about 005T after pulsed discharge. From this moment the synthetic jet diffused rapidly

resulting in the decrease of peak velocity and vorticity. For the present sparkexcited actuator and the excitation parameters

the sparkexcited synthetic jet was strengthened with the increase of excitation frequency and capacitance energy storage.