Broadband noise prediction of a counter rotating open rotor based on LES simulation with phase-lagged assumption (draft)

This paper presents the broadband noise analysis of a Counter Rotating Open Rotor (CROR) configuration. The numerical study is based on hybrid approach: Large Eddy Simulation (LES) code solves near-flow field CROR configuration and near-to-far-field propagation then predicted by Ffowcs Williams–Hawkings analogy either solid or porous formulation. LES solver uses phase-lagged assumption with proper orthogonal decomposition for data storage. approach validated against wind tunnel experimental (AI-PX7) at three different operating points focused noise. simulations shows predominant effect rear rotor suction side radiated an increasing contribution span location. source related to impingement front wakes development leading edge vortices that induce large pressure fluctuations close side.