This paper focuses on the development of an active flow control system dedicated to the mitigation of airframe noise produced by Counter Rotating Open Rotor propeller, through the erasing of its pylon wake. This aerodynamic furtivity system relies on a coupled boundary layer scooping/blowing strategy. The optimization process of the flow control system, based on two- and three-dimensional Reynolds Averaged Navier Stokes computations, has allowed designing the wind tunnel model and pre defining the flow control parameters -scooping and blowing mass flow rates- to apply such as to mitigate the pylon wake. It is first described. The analysis of the efficiency of the active flow control system in erasing the pylon wake is then conducted on the basis of wind tunnel experiments. They are composed of pressure coefficient distribution along the pylon profile, transverse profiles of total pressure at various streamwise and spanwise positions in the wake of the pylon and on stereoscopic Particle Image Velocimetry transverse plane measurements at various streamwise positions. These results allow identifying nominal operating points, where the active flow control system fully erases the pylon wake. They also highlight the robustness of the flow control system in mitigating the wake of the pylon despite moderate variations of the flow conditions.
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