A Coupled Field Finite Element Modeling Procedure for Design of a Synthetic-Jet Actuators

Abstract

The development and validation of a modeling procedure used for design of piezoceramic-driven, SJAs, which is based on ANSYSTM FE software, is described. This approach holds the advantage over others in that it fully couples the complex physical interactions among the structure of the actuator, the working fluid, and the driving piezoelectric actuation. The procedure employed was two FEMs: one used a fully coupled acoustic-structural-piezoelectric, while the other used a fully coupled fluid-structure-piezoelectric field formulation. The acoustic-structural-piezoelectric model was useful in that it was used to predict quickly the acoustic and structural resonant frequencies of the actuator device for rapid design. While the fluid-structural-piezoelectric model was more computationally expensive than the acoustic-structural-piezoelectric model, it was superior in that it provided insight into transient synthetic-jet output velocity time and spatial dependence, displacement, and structural stress time histories. This procedure allows investigation of actuator design and of fluid dynamics of synthetic-jets. The models’ predictions were compared to experimental data obtained for a sample actuator configuration and good agreement was found. Both FEMs were defined for an axisymmetric, single-diaphragm piezoelectric actuator, but the procedure may be extended to other actuator geometries.