Numerical simulation of micro-fabricated zero mass-flux jet actuators

Abstract Computational fluid dynamics can play an important role in the design of microelectromechanical systems (MEMS)-based actuators, allowing an investigation of the underlying physical behavior of devices before proceeding to expensive manufacturing processes. Here, we present the results of a series of numerical simulations of synthetic jet actuators, so-called because they synthesize jets from the working fluid. The primary characteristic of these actuators is that over a cycle, the net mass flux is zero, yet the mean momentum flux is non-zero. The simulations consider both the internal and external flow-fields of a micro-scaled device, with the membrane motion specified using a simplified structural analysis. Key features of the flow in the external, orifice and cavity regions are presented and discussed. The actuator output is observed to vary linearly with a non-dimensional input parameter, and this may guide the design of flow control systems that use synthetic jet actuators. Finally, our fabrication strategy for a MEMS-based synthetic jet actuator is presented.