Closed-Loop Active Flow Control - A Collaborative Approach

Abstract

The Collaborative Center of Control Science (CCCS) at The Ohio State University was founded very recently with funding from the Air Force Research Laboratory to conduct multidisciplinary research in the area of feedback control, with applications such as cooperative control of unmanned air vehicles (UAVs), guidance and control of hypersonic vehicles, and closed-loop active flow control. The last topic is the subject of this paper. The goal of this effort is to develop tools and methodologies for the use of closedloop aerodynamic flow control to manipulate the flow over maneuvering air vehicles and ultimately to control the maneuvers of the vehicles themselves. It is well known in the scientific community that this is a challenging task and requires expertise in flow simulation, low dimensional modeling of the flow, controller design, and experimental integration and implementation of these components along with actuators and sensors. The CCCS flow control team possesses synergistic capabilities in all these areas, and all parties have been intimately involved in the project from the beginning, a radical departure from the traditional approach whereby an experiment is designed and constructed, data are collected, a model is developed, and a control law is designed, i.e. the system is assembled for validation in a sequential fashion. The first problem chosen for study, control of the noise created by a shallow cavity placed in a flow, has specific relevance to the needs of the Air Force. For example, significant pressure fluctuations in an aircraft weapon bay can lead to structural damage to the air vehicle, to the stores carried in the cavity, and especially to the electronics carried onboard the stores. The team has been working together for a relatively short period of time. Nevertheless, significant progress has been made in the development of various components of the closed-loop cavity flow control problem. The paper will present and discuss the progress made to date and future plans.