2D ACTIVE LINER EXPERIMENTAL RESULTS IN ACOUSTIC FLOW DUCT FACILITY

This paper is focused on experimental characterization of new active liners technologies in acoustic flow duct facilities (FDF). These measurements have been performed in the NLR (Netherlands Aerospace Center). Different configurations of passive and active treatments have been tested using the same grazing flow conditions (Mach 0.3) in an aeroacoustic test bench: 1 conventional liner (standard SDOF sandwich panels with honeycomb core) used as reference and a 2D active liner based on an array of electroacoustic absorbers. The grazing flow test campaign comprises acoustics and aerodynamics measurements to characterize the aeroacoustics flow conditions, the membrane behavior, the acoustic impedance and the resulting insertion loss.