BEAM Technologies, Inc. and Clarkson University propose to design and demonstrate a robust, scalable feedback controller that utilizes Micro Electro-Mechanical System (MEMS) sensors and actuators to control flow separation on lifting surfaces and in airbreathing engine inlets---offering the potential of significantly higher mission effectiveness in weapons like LOCAAS. Separation is a macro-scale phenomenon. Micro-scale actuation requires exploitation of physical mechanisms that amplify the effects of small-scale input. Viable systems must also extract information sufficient for control from physically measurable input. Through experiments in the ActiveWing facility at Clarkson University, we have demonstrated technology that utilizes wall-mounted sensors and pulsed jets to produce order-one effects with order-epsilon input. Design of a closed-loop controller is the natural next step, and we will integrate our proven technology into candidate algorithms that will be tested during Phase I. Leveraging our expertise in control system design, we will evaluate controllers that utilize boundary layer approximations, stability analyses, optimal design, feedback control theory, and reduced-order modeling. The demonstrated system will consist of an array of pressure/shear stress micro-sensors on the lifting surface that send data in real time to a digital signal processor. A controller will identify locations of incipient separation, based on input from the wall and autopilot data. Pulsed jets will be activated at the locations of incipient separation, using algorithms that compute optimal strength and frequency. Increased performance requirements and tighter constraints on volume and weight force airframes closer to their design limits. Jet engine manufacturers must reduce surge margins for the same reasons. Airframe and propulsion system designers need new tools for these new challenges and all stand to gain from an experimentally validated computational environment for designing MEMS-based, flow separation control systems.
