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| 2001-2002 Fluids Seminar Page |
Mechanical, Materials & Aerospace Engineering Department
Illinois Institute of Technology
Abstract-
After a couple of decades of intensive basic research in Active Flow Control (AFC), the aerospace industry is now receptive to conducting demonstrations to explore the potential (feasibility, affordability and performance) of these techniques for a wide range of aircraft such as the ATT, V-22, QTR, XV-15, as well as various Advanced Rotorcraft and Unmanned Air Vehicles (UAV). Zero-net mass flux oscillatory jets introduced from spanwise slots at various locations on the upper surface of steady and oscillating airfoil models are shown to be effective in controlling lift, moment and drag coefficients over the range of Mach numbers over 0.4. This control is demonstrated over a wide range of mean angles of attack from light to deep stall conditions on several airfoil cross sections with or without flaps. Maintaining the non-dimensional frequency and amplitude of the forcing unchanged, leads to comparable modifications of the aerodynamic coefficients throughout this Mach number range. Near the higher end of this Mach number range, local supercritical conditions are experienced near the leading edge and shocks are present. Even in these cases the flow control was found to be effective with slot locations near the location of the shock. Therefore, it appears that this active flow control technique is only limited by the ability to generate the adequate forcing conditions at the higher Mach numbers required for applications such as rotorcraft, and aircraft requiring high lift for short takeoff and landing or controllable drag for rapid maneuverability. The presentation will focus on the flow physics in the regions where the control is introduced and on the scaling of the control parameters.
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