Feedback Flow Control for a Three-Dimensional Turret

Clear Science Corp. proposes to design wind tunnel and computational experiments for testing feedback systems that control flow over a three-dimensional turret, motivated by the relationship between flow dynamics and the performance of an optical system housed in the turret. The closed-loop control system that will be developed in Phase I consists of a reduced-order model of the flow, measurement-based estimators, and control input-performance output algorithms and regulators that relate variables in the low-dimensional model to actuator inputs and the control objective. The measurement system will utilize a small array of sensors located on the turret to estimate the flow dynamics above the turret. Several representations of performance output will be evaluated beginning with direct relationships between flow dynamics and the low-dimensional model variables. A computational platform will be developed for designing control systems through control-in-the-loop CFD simulations. The experimental test design will consist of two stages: controller design through off-line data acquisition and control-in-the-loop wind tunnel runs. In the first stage, three-component Particle Image Velocimetry measurements and surface measurements will provide data for constructing the low-dimensional model and measurement-based estimator. In the second stage, 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.