Feedback Flow Control for a Three-Dimensional Turret

Clear Science Corp. proposes to develop feedback systems that control flow over a three-dimensional turret and demonstrate the technology through control-in-the-loop Computational Fluid Dynamics (CFD) simulations and wind tunnel tests. A parallel-track plan is designed to meet two broad objectives: development and demonstration of systems for controlling flow separation with an emphasis on closed-loop control and a broader investigation of the relevant physics associated with the flow including separation, turbulence, density fluctuations, shocks, shock-boundary layer interaction, and aero-optical distortion. In the experimental demonstrations, Particle Image Velocimetry (PIV) measurements will be used to construct low-dimensional models of the flow via the method of Proper Orthogonal Decomposition. PIV and surface-pressure measurements will be used to construct measurement-based estimators through correlations between surface pressure and the unsteady evolution of model variables. Performance-output algorithms will be developed to establish relationships between model variables and the control objective(s). The estimators, input-output algorithms, and regulators will be integrated into a command-and-control system for controlling flow over the three-dimensional turret in a series of wind tunnel tests and control-in-the-loop CFD simulations. Experimental testing will focus on closed-loop control of separation in subsonic flows. CFD tests will target a range of physics associated with sub- and transonic flows.