Experimental Investigation of Flow Characteristics of Synthetic Jet and It's Preliminary Application to Combustion

The velocity distributions of synthetic jet were measured with Hot-wire anemometer.Experimental result shows that two distinct regions exist in the flow-field created by the actuator.Close to the slot-exit,the mean centerline velocity accelerates downstream to a maximum at distance of approximately 10～15 slot-width,when signal frequency is 980 Hz and amplitude is 40 V.At streamwise distance larger than approximately 10～15 slot-width,the flow pattern changes as conventional jet.Velocity profile across the synthetic jet appears like the profile in conventional jet,but velocity gradient is much large.At the exit of combustor,excitation using synthetic jet can improve the distribution of temperature and decrease contents of NO_x.Synthetic jet is effective for active flow control purpose.