Active Separation Control at the Pylon-Wing Junction of a Real-Scale Model

Abstract

The effect of active flow control on local flow separation behind the installation Location of an ultra-high-bypass-ratio nacelle is investigated in a real-scale experiment at the TsAGI T-101 wind tunnel. The investigated model represents a swept 2.5D-section of the pylon-wing junction in landing configuration. A flow control system employing periodic excitation is integrated into the unprotected leading edge inboard of the pylon. Tuft visualization as well as pressure and force measurements are used to investigate the vortex-dominated base flow and the effect of active flow control. It is shown that the flow control effect is governed by the normalized parameters of flow control, the momentum coefficient and the velocity ratio, and is largely independent of the free-stream Mach and Reynolds number within the investigated range. The influence of a variation of the momentum coefficient c_µ on the lift gain is investigated. At the highest Reynolds number of Re = 10.7 · 10^6 an application of active flow control with c_µ = 1:08% fully eliminates local separation and increases total lift by approximately 2% of the respective baseline value across a range of 5 degrees in angle of attack.