Predicting the rotor-stator interaction acoustics of a ducted fan engine

A Navier-Stokes computation is performed for a ducted-fan configuration with the goal of predicting rotor-stator noise generation without having to resort to heuristic modeling. The resulting pressure field in the inlet region is decomposed into classical infinite-duct modes, which are then used in either a hybrid finite-element/Kirchhoff surface method or boundary integral equation method to deduce the far field noise. Comparisons with experimental data are presented, including rotor wake surveys and far field sound pressure level for 2 blade passage frequency (BPF) tones.