Reducing Transient Energy Growth in a Channel Flow Using Static Output Feedback Control

Huaijin Yao, Yiyang Sun, Talha Mushtaq, Maziar S. Hemati

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Transient energy growth of flow perturbations is an important mechanism for laminar-to-turbulent transition that can be mitigated with feedback control. Linear quadratic optimal control strategies have shown some success in reducing transient energy growth and suppressing transition, but acceptable worst-case performance can be difficult to achieve using sensor-based output feedback control. In this study, we investigate static output feedback controllers for reducing transient energy growth of flow perturbations within linear and nonlinear simulations of a subcritical channel flow. A static output feedback linear quadratic regulator (SOF-LQR) is designed to reduce the worst-case transient energy growth due to flow perturbations. The controller directly uses wall-based measurements to optimally regulate the flow with wall-normal blowing and suction from the upper and lower channel walls. We show that SOF-LQR controllers can reduce the worst-case transient energy growth of flow perturbations. Our results also indicate that SOF-LQR controllers exhibit robustness to Reynolds number variations. Further, direct numerical simulations show that the designed SOF-LQR controllers increase laminar-to-turbulent transition thresholds under streamwise disturbances and delay transition under spanwise disturbances. The results of this study highlight the advantages of SOF-LQR controllers and create opportunities for realizing improved transition control strategies in the future.

Original languageEnglish (US)
Pages (from-to)4039-4052
Number of pages14
JournalAIAA journal
Issue number7
StatePublished - 2022

Bibliographical note

Funding Information:
This material is based upon the work supported by the Air Force Office of Scientific Research under award number FA9550-19-1-0034, monitored by Gregg Abate.

Publisher Copyright:
© 2022 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.


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