DOI: 10.1615/TSFP7
OPEN AND CLOSED-LOOP EXPERIMENTS TO REATTACH A THICK TURBULENT BOUNDARY LAYER
要約
Open and closed-loop control experiments were successfully performed to reattach a thick turbulent boundary layer, thanks to large scales of the facility (i.e. wind tunnel Carlier & Stanislas (2005)). This extends to large Reynolds numbers and large time scales the range of flow conditions for which open and closed-loop control configurations were investigated for turbulent flow separation configurations. Experiments were performed at three Reynolds numbers based on the momentum thickness of the turbulent boundary layer, varying from Reθ ~ 7500 to 12600. First open-loop tests were conducted to identify the systems. They were found to behave like a first order linear one, with coefficients that need to be adapted depending on the Reynolds number. Then, simple controllers (Proportional-Integral and Linear Quadratic Regulator) were implemented in closed-loop configurations. They were able to significantly improve the reactivity of the system and consequently the cost of the control. A test of robustness was performed from variations of the free-stream velocity which highlights the need to improve it using more complex controllers.