This project focuses on the development and application of piezoelectric linear actuators in different examples of active flow control. The primary goal of this research is to build and quantify custom piezoelectric bending beam actuators; the piezoceramic used is Lead Zirconate Titanate. Different actuators with varying parameters such as piezoelectric thickness and beam length are being fabricated and tested. These devices are actuated with a periodic function, resulting in an oscillating platform on which to mount different flow control devices.

Currently many vertical tails on commercial aircraft are oversized in order to compensate for an extremely rare and specific emergency scenario: A single engine out in high crosswind during takeoff and landing. Our goal is to improve the performance of a smaller vertical tail, which would allow for higher deflection angles, and therefore higher sideforce, in order to compensate for the high yaw produced during these emergency scenarios. This would allow for a significant decrease in weight and drag, since the majority of an airplanes flight time is spent at cruise conditions.

The addition of active flow control devices, such as synthetic jet actuators, on three-dimensional aerodynamic surfaces (i.e. vertical tail, wings, etc.) can lead to significant flowfield modification for beneficial improvements in aerodyanmic performance. Previous work by Dr. Nicholas Rathay and collaborators on this project focused on augmenting the side force generated by synthetic jets through separation control on scaled vertical tail models. Since commercial airplane tails are sized based on a single engine failure situation, they are larger than necessary for normal flight.

In general, the behavior in the wake of a wall-mounted circular cylinder with finite height is considerably different from that of two-dimensional bluff bodies. Unlike the flow field associated with a conventional 2D cylinder, a cantilevered finite-span cylinder is largely influenced by the presence of a spanwise (i.e., along the height of the cylinder) velocity component, most notably the downwash issued from the free end of the cylinder.

This research project is to explore the evolution of a synthetic (zero net mass flux) jet and the flow mechanisms of its interaction with a cross flow.

Synthetic jet actuators (SJA) are zero-net-mass-flux devices that produce vortex rings which break down to form a jet, injecting momentum into the surrounding flow field (Fig. 1). Since SJA are self-contained electrically-powered devices, they have considerable weight and infrastructure advantages over other aerodynamic flow control methods, such as conventional steady blowing jets or sweeping jets which require a pressurized air source. In this project, we have derived a semi-empirical model to guide design parameter selection, developed a novel fabrication process for SJAs (Fig.