Design of a single-crystal piezoceramic-driven synthetic-jet actuator

Synthetic-jet actuators have been intensely studied recently. The interest in these devices is elicited by their usefulness in fluid-control applications, including boundary-layer control, combustion control etc. A synthetic-jet actuator is a zero-net-mass-flux device, and is comprised of a diaphragm mounted to enclose a volume of fluid in a cavity. The diaphragm bends sinusoidally, and fluid is periodically absorbed into and ejected from the cavity through an orifice. The outflow entrains the fluid around it and establishes a mean jet flow at a distance from the source. Piezoceramic materials have been used to drive the vibrating diaphragm, where the piezoceramic is glued directly to a silicon diaphragm. In combustion systems, improved turbulent mixing of air and fuel proper can significantly improve efficiency and reduce pollution. In boundary-layer separation control applications, synthetic-jets are used to improve aerodynamic performance by delaying separation and stall over the airfoil. The current work describes the modeling and design of a single-crystal piezoceramic-driven synthetic-jet actuator, and demonstrates that the efficiency of the actuator increases when single-crystals piezoceramic materials are used instead of the more conventional polycrystalline piezoceramics.