Transient energy growth (TEG) is a primary mechanism for bypass transition in many wall-bounded shear flows. Here, we investigate the efficacy of reducing TEG in a linearized channel flow with feedback controllers that use wall shear-stress sensors and wall-normal blowing/suction actuators. Owing to established performance limitations of observer-based controller designs within the context of TEG, we study static output feedback linear quadratic regulation (SOF-LQR) strategies for control. SOF-LQR is found to outperform optimal observer-based feedback designs, and to reduce TEG of spanwise disturbances relative to the uncontrolled flow. We further show that by introducing an appropriate set of additional observables, SOF-LQR controllers can reduce TEG associated with streamwise and oblique disturbances as well. In fact, we show that by selecting a small number of appropriate observables, SOF-LQR controllers can fully recover full-state LQR performance.
|Original language||English (US)|
|Title of host publication||AIAA Scitech 2019 Forum|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|State||Published - Jan 1 2019|
|Event||AIAA Scitech Forum, 2019 - San Diego, United States|
Duration: Jan 7 2019 → Jan 11 2019
|Name||AIAA Scitech 2019 Forum|
|Conference||AIAA Scitech Forum, 2019|
|Period||1/7/19 → 1/11/19|
Bibliographical noteFunding Information:
This material is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-17-1-0252, monitored by Dr. Gregg Abate.