Apparatus And Method For Enhancement Of Aerodynamic Performance By Using Pulse Excitation Control

Abstract

One aspect of the apparatus disclosed herein is a system for modifying an aerodynamic property of an aerodynamic surface in a fluid flow. The fluid flow could comprise a free stream fluid flow, or an internal fluid flow, such as in a nozzle, diffuser, or compressor. The system of the preferred embodiment comprises a synthetic jet actuator embedded in an aerodynamic surface. In one aspect, the aerodynamic surface may be a wing. The synthetic jet actuator typically has a jet housing defining a chamber, where the chamber is in fluid communication with the fluid. This fluid communication may be accomplished via an orifice in a wall of the housing. Additionally, a portion of said housing is preferably moveable such that the volume of the chamber can be adjusted. The system also comprises a device for changing the position of the moveable portion of the housing at a predefined frequency. In this way, the synthetic jet actuator is pulse modulated in order to enhance the synthetic jet actuator's performance. In another aspect, the invention may be seen as a method of controlling a synthetic jet actuator. The method preferably comprises the steps of driving a synthetic jet actuator at a first frequency and turning the synthetic jet actuator on and off at a second frequency. The synthetic jet actuator interacting with a fluid flow to alter the fluid flow field.