Structural–fluidic–acoustic computational modelling and experimental validation of piezoelectric synthetic jet actuators

In this study, coupled structural–fluidic–acoustic modelling of piezoelectric diaphragm driven synthetic jet actuators is conducted computationally for the first time. The aim is to demonstrate the importance of piezoelectric diaphragm structural modelling and the effects of acoustics coupling to compute accurate synthetic jet exit jet velocity. Two different synthetic jet actuator orifice–diaphragm configurations are studied in which the orifice is parallel and adjacent to the diaphragm, namely, opposite and adjacent synthetic jet actuators, respectively. In investigating the aforementioned configurations, cavity acoustic and mechanical resonance frequencies are identified within ± 100 Hz, compared to in-house experimental measurements of laser vibrometry and hot-wire anemometry. The numerical peak jet velocity differs from the experimental value at the diaphragm mechanical resonance by 5.4% and 0.3% for opposite and adjacent synthetic jets, respectively. Further analysis of velocity and vorticity fields showed that no vortex formation is observed in the cavity of the adjacent synthetic jets, despite having similar exit jet velocity of the opposite synthetic jet configuration.