Abstract
Jet flows generated by a circular synthetic jet actuator were investigated experimentally by using a hot-wire anemometer. The mean and turbulent velocity profiles were measured for two forcing conditions of alternating flow in an orifice nozzle. An equivalent jet velocity is defined based on the measured momentum of synthetic jets to compare with the velocity profiles in a circular jet. The results indicate that the synthetic jets show the larger spreading rate in jet width and the higher decay rate in velocity than those of a circular jet. This wider spreading can be caused by the stronger turbulent motions in the synthetic jets. Two synthetic jets whose momentum is similar but forced by different frequencies show the different jet evolutions. This difference is attributed to the change in lifetime of vortex rings emitted from the orifice nozzle.
