Active Control of Compact Diffusing Inlets Using SMA-Actuated Micro-Vortex Generators and Non-Intrusive Hot-Film Sensors

Conventional passive control systems are associated with large penalties at off-design conditions that are frequently encountered in a typical flight envelope. The proposed innovation will result in the development of an active control system with highperformance gains at all flight conditions. A compact, diffusing inlet incorporating active flow control will be developed for Unmanned Combat Air vehicles (UCAV). A matrix of micro-thin, surfact hot-film sensors operated by automated Constant VoltageAnemometer (CVA) system will be used for measuring diffuser boundary-layer characteristics. Tao Systems' flow-diagnostics techniques will be used for real-time identification and tracking of unsteady flow separation and the generation of streamwisevortices in the duct. Shape Memory Alloy Actuated Micro-Vortex Generators (SMA-MVG)will be used for active control of boundary-layer characteristics in the inlet diffuser to minimalize flow distortion and maximize pressure recovery. Rule based controlalgorithms will be developed for feedback control to optimize active flow control. These enabling component technologies will be integrated into a compact, low-obserable, S-shaped diffusing inlet.