A Comparison of Unimorph and Bimorph Circular Piezoceramic Discs For Synthetic Jet Actuator Performance

Synthetic jet actuators have certain advantages for the full-scale implementation as a new generation active flow control device. They are compact in size and self-containing with no requirement for piping. Even though further research is required, they can potentially achieve high enough jet velocity to have full-scale application in the aerospace industry. Relatively low jet velocity is a limiting factor for a potential industrial application thus, the jet velocity should be increased to match the flight conditions and to provide effective flow control.
Piezoelectrical driven actuators typically utilize a single piezoceramic bonded on a substrate metal such as brass which is known as a unimorph actuator. This study focuses on the performance indicators of synthetic jet actuators by comparing a unimorph piezoceramic diaphragm with a similar dimension of a bimorph one. The experimental work involves the measurement of diaphragm displacement profile, in-cavity pressure, output jet velocity, and electrical power consumed by each diaphragm on a common actuator geometry.
The preliminary results show that the bimorph piezoceramic promotes a doubled higher diaphragm displacement with a larger output jet velocity with increased power consumption.