Abstract
Fluid systems are most efficient for fully attached flows, and designers therefore seek to avoid flow separation. Active flow control can help achieve this goal, and closed-loop control offers improved performance at off-design conditions. However, this requires feedback of accurate state estimates to the controller in real time. This motivates a physics-based, state-estimation technique that economically extracts key dynamical features of the flow. This work aims to extract dynamical characteristics of a laminar separation bubble on a flat plate at a chord Reynolds number of 105 using a linear array of unsteady surface pressure measurements. First, DynamicMode Decomposition (DMD) is employed on high-dimensional time-resolved PIV velocity and corresponding estimated pressure fields to identify the dynamically relevant spatial structure and temporal characteristics of the separated flow. Then, results are presented of various open-loop control cases using pulse-modulation of a zero-net mass-flux actuator slot located just upstream of separation. Real-time estimates of the dynamical characteristics are provided by performing on- line DMD onmeasurements froma linear array of 13 unsteady surface pressure transducers. The results show that this method provides reliable estimates of the modal characteristics of the sep- arated flow subject to forcing at a rate much faster than the characteristic time scales of the flow. Therefore, online DMD applied to the surface pressure measurements provides a time-varying linear estimate of the evolution of the controlled flow, thereby enabling closed-loop control.
Original language | English (US) |
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Title of host publication | 47th AIAA Fluid Dynamics Conference, 2017 |
Publisher | American Institute of Aeronautics and Astronautics Inc, AIAA |
ISBN (Print) | 9781624105005 |
DOIs | |
State | Published - 2017 |
Event | 47th AIAA Fluid Dynamics Conference, 2017 - Denver, United States Duration: Jun 5 2017 → Jun 9 2017 |
Publication series
Name | 47th AIAA Fluid Dynamics Conference, 2017 |
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Other
Other | 47th AIAA Fluid Dynamics Conference, 2017 |
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Country/Territory | United States |
City | Denver |
Period | 6/5/17 → 6/9/17 |
Bibliographical note
Publisher Copyright:© 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.