Novel High Control Authority Actuators for Jet and Cavity Noise Reduction

Abstract

Jet and cavity flows have been of great interest both for basic science and engineering applications. In order to effectively control these flows several groups have undertaken the development of flow control actuators. The aeroacoustics research group within the Fluid Dynamics Research Center at the Illinois Institute of Technology has been involved in the development of high control authority and high frequency actuators for jet and cavity noise reduction. This paper is an overview of the development and the application of three novel actuators developed by our group for controlling jet and cavity flows. Three actuators are presented in this overview (i) ultrasonic powered resonance tube actuator, (ii) cylindrical rod that sheds vortices in the upstream boundary layer and (iii) a miniature shock tube actuator. (i) and (ii) produce high frequency actuation (relative to shear layer frequencies) whereas (ii) and (iii) produce high control authority actuation. The cylindrical rod lies at the intersection of high frequency and high control authority actuation (see Figure 1). An account of the development of these actuators is presented along with representative depictions of their effectiveness in jet and cavity flows.