Research on the Structures and Geometric Parameters of Synthetic Jet Actuator

摘要

Synthetic jet actuator(SJA)is a prominent device for active flow control(AFC).Fluid was expelled out of actuator through an orifice exit on the top of the cavity by the periodically oscillating of the membrane on the bottom,on which a piezoelectric patch was adhered to drive the SJA.A series of continuous vortex pairs were formed by the shearing between the expelled fluid and the surrounding fluid,and can be used as a prominent AFC method.The conventional flat membrane and cymbal structure membrane SJA were studied,and different geometric parameters were designed to optimize the SJA structure with the purpose of improving the output velocity and enhancing the control capability of actuator.Frequency responses of the membrane were examined and the velocity along the axis of the SJA orifice exit was measured by hot-wire anemometer.The geometric parameters had a great influence on the output velocity as well as the resonance frequency.The cymbal membrane structure emitted higher output velocity compared with flat copper membrane.The FFT method was used to analyze the synthetic jet characteristics.