Abstract:

A new piezoelectric synthetic jet actuator (PSJA) equipped with a half cymbal metal-piezoelectric composite membrane is proposed for the purpose of improving the output jet velocity and enhancing the controlling ability of synthetic jet actuator (SJA) for active flow control. Three kinds of half cymbal structure membranes as well as a plane one are manufactured and studied. The frequency responses and time-averagedjet velocity along the axial distance as well as along both sides from the exit of the SJA are measured and compared. The results show that the time-averagedjet velocities synthesized from the three actuators with half cymbal membranes improved by 50%, 25%, and 46% respectively as compared with the actuator with a plane embrane. Then the effects of cavity geometric parameters of PSJA with half cymbal membranes on output jet velocity are experimentally investigated. The results show that there is an optimal combination of these parameters that causes higher time-averagedjet velocity and lower velocity decay along the axial distance form exit.

Key words: synthetic jet, piezoelectric actuator, cymbal structure, geometric parameter, membranes