Experimental Performance Comparison of Unimorph- and Bimorph-Driven Synthetic Jet Actuators

This study presents an experimental comparison of synthetic jet actuators employing unimorph and bimorph piezoelectric diaphragms under identical cavity-orifice geometries. Two cavity-orifice arrangements, namely, opposite and adjacent configurations, are examined over a broad range of actuation frequencies and supply voltages. Diaphragm displacement, jet velocity, electrical power consumption, fluidic-to-electric power conversion efficiency, and thermal behavior are systematically characterized. The results show that the bimorph diaphragm produces significantly larger displacements and higher jet velocities, achieving peak exit velocities approaching [Formula: see text]. However, this enhanced performance is accompanied by substantially higher current consumption and greater thermal accumulation during sustained operation. In contrast, the unimorph-driven actuator generates lower jet velocities but provides approximately 1.6 times higher fluidic-to-electric conversion efficiency owing to its lower electrical power demand. The adjacent cavity-orifice arrangement reduces both jet velocity and current draw relative to the opposite configuration while maintaining similar overall response characteristics. These findings highlight the tradeoffs between jet performance, energetic efficiency, and thermal behavior, providing practical guidance for the implementation of synthetic jet actuators in aerodynamic flow control applications.