A review of CAA for fan duct propagation and radiation, with application to liner optimisation

This article reviews the application of Computational Aero-Acoustics (CAA) to the prediction of acoustic propagation in turbofan ducts. The challenge of resolving the radiated sound field for realistic nacelle geometries is discussed and evidence is presented to indicate that current CAA is able to represent the effect of in-duct liners on far-field measured rig and engine data. Two approaches are presented for incorporating CAA predictions within liner optimisation schemes for a turbofan intake.