Investigation of Wall-Pressure Fluctuations Characteristics on a NACA0012 Airfoil with Blunt Trailing Edge

The trailing edge noise, or the so-called self-noise of an airfoil, significantly contributes to the broadband noise in various configurations such as high bypass-ratio engines and counter-rotating open rotors. The present work aims at characterizing the wall-pressure fluctuations in the turbulent boundary layer just upstream the trailing edge, that are known to shape the trailing edge noise spectrum. These investigations are carried out using large- eddy simulations, with the massively parallel compressible solver CharLESX, of the flow over a truncated NACA0012 airfoil at Rec = 4×105 for angles of attack α = 0◦ and α = 6.25◦. Unsteady wall-pressure signals are recorded using several thousands of probes distributed over the suction side. We focus on data-processing the pressure signals to extract quantities crucial to trailing edge noise modelling: the convection velocity Uc, the spanwise correlation length lz and the spectrum of the wall-pressure fluctuations Φpp